Endodontic Lesions Research Articles

Endodontic microsurgery: outcomes and prognostic factors

This review addresses endodontic microsurgery procedures compared with traditional surgery and aims to review factors related to the success and failure of endodontic microsurgery from the existing literature. Periodontal involvement and tooth position are patient- and tooth-related factors known to have an effect on the outcome of apical surgery. Factors related to successful outcome have been reported and include whether the mineral trioxide aggregate used to obturate the apical portion of the root after surgery was fast or slow setting. Although not statistically significant, larger difference in the success rate between slow- and fast-setting MTA groups was observed in teeth with endodontic-periodontal lesions than in teeth with isolated endodontic lesions suggesting that the faster setting root-end filling material is most advantageous, particularly when endodontic lesions have periodontal involvement. Endodontic microsurgery has witnessed major advances and is currently regarded as an integral part of standard endodontic treatment. Improved visibility and illumination because of the operating microscope, advances in ultrasonic instrument technology, and the development of more biocompatible root-end filling materials have contributed to the technical advances that have led to higher success rates in endodontic microsurgery compared with traditional surgery.

Oral diseases in Geriatric patients; pattern of presentation and challenges of management in a developing economy

Objectives: To determine the pattern of orofacial diseases, oral care interventions and co-morbidities in the elderly Background: Aging is accompanied by changes in every part of the body including orofacial tissues. These changes are often overlooked when considering health care demands of the elderly. Empirical insights into the pattern and risk factors to oral diseases of elderly Nigerians which are of public health importance are scarce. Materials and Methods: Electronic records of 275 elderly patients aged ≥60 years who attended the dental unit of our facility between 1st January 2013 and 31st December 2015 were analyzed. Data extracted included the sociodemographic characteristics, reasons for encounter, orofacial diagnoses and co-morbidities. Results: The mean age of the patients studied was 70.8 ± 7.5 years and 185 (67.3%) of these patients were females. The major reasons for the dental visits were toothache (54.9%) and cleaning of teeth (14.2%). Periodontal diseases (68.0%) and endodontic lesions (11.3%) were the commonest orofacial diagnoses. Overall, there were 780 (2.8 per elderly) missing teeth. Scaling and polishing 140 (50.9%) and tooth extraction 98 (35.6%) were the most frequent orofacial procedures. There was an average of 1.5 co-morbid medical condition per elderly patient studied. Hypertension (51.3%) and osteoarthritis (29.1%) were the most common co-morbid medical conditions in the patients we studied. Conclusion: Periodontal and endodontic lesions were the commonest orofacial infections in these patients while hypertension and osteoarthritis were the most common co-morbid medical conditions seen amongst elderly patients seen at the dental unit of our geriatric health centre. These findings will be useful for the setting up and management of elderly patients needing oral health care in Nigeria.

Clinico-radiologic features of molar-incisor malformation in a case series of 38 patients: A retrospective observational study.

Molar-incisor malformation (MIM) is a recently defined dental abnormality of molar root and incisors, and introduced as one of the causes of periapical and periodontal abscess. The purpose of this study was to investigate the clinical and radiological features of MIM, with special emphasis on various medical history. A total of 38 patients with MIM were included in this study. Radiographic features and clinical data, including medical history, chief complaint, associated complications, treatment, and prognosis, were retrospectively investigated. On radiographs, the affected molars showed short, slender, underdeveloped roots and constricted pulp chambers. All affected incisors and canines exhibited dilacerated short roots, wedge-shaped defect on the cervical part of the crown. Complications included periodontal bone loss (52.6%), endodontic lesion (50.0%), and endodontic-periodontal lesion (28.9%). The medical histories of the patients with MIM indicate that almost all (94.7%) were hospitalized due to problems during the neonatal period. MIM may cause various dental problems, such as periapical and periodontal abscess and early loss of the affected teeth. The early diagnosis of MIM on radiographs and appropriate treatment will contribute to a favorable prognosis, especially for young and adolescent patients.

Organic resolution function and effects of platinum nanoparticles on bacteria and organic matter.

Rapid progress has been made in terms of metal nanoparticles studied in numerous fields. Metal nanoparticles have also been used in medical research, and antibacterial properties and anticancer effects have been reported. However, the underlying mechanism responsible for these effects has not been fully elucidated. Therefore, the present study focused on platinum nanoparticles (PtNPs) and examined their antibacterial properties and functional potential for decomposing organic matter, considering potential applications in the dental field. PtNPs were allowed to react with dental-related bacteria (Streptococcus mutans; Enterococcus faecalis, caries; Porphyromonas gingivalis, and endodontic and periodontal lesions). Antibacterial properties were evaluated by measuring colony formation. In addition, PtNPs were allowed to react with albumin and lipopolysaccharides (LPSs), and the functional potential to decompose organic matter was evaluated. All evaluations were performed in vitro. Colony formation in all bacterial species was completely suppressed by PtNPs at concentrations of >5 ppm. The addition of PtNPs at concentrations of >10 ppm significantly increased fragmentation and decomposition. The addition of PtNPs at concentrations of >125 pico/mL to 1 EU/mL LPS resulted in significant amounts of decomposition and elimination. The results revealed that PtNPs had antibacterial effects against dental-related bacteria and proteolytic potential to decompose proteins and LPS, an inflammatory factor associated with periodontal disease. Therefore, the use and application of PtNPs in periodontal and endodontic treatment is considered promising.

Local risk indicators – Consensus report of working group 2

In implant dentistry, plaque control and oral hygiene practices are essential to limit the risk of complication and failure in the long term. All conditions around an implant in function that influence the load and pathogenicity of the microbiota are considered local risk indicators. They concern the prosthetic suprastructure design and the possibility for the patient to easily access each implant for plaque removal. Use of cemented prostheses should be limited to avoid excess cement acting as a foreign body and leading to peri-implant disease. The crown margins should be supramucosal, and the connection should be precise to avoid a gap between the implant and the suprastructure. Every implant system is characterised by a specific design, surface texture and connection type. These features may influence peri-implantitis development and progression, and the clinician should consider the risk of infection when selecting an implant. The soft-tissue conditions around the implant, the width of keratinised mucosa, and the phenotype and thickness of the mucosa are also considered major risk indicators, as the presence of any mucosal defect around an implant can increase plaque accumulation and result in tissue inflammation. The pathogenicity of the microbiota around an implant is primarily dependent on pocket depth. Deep pockets around implants should be avoided and, if present, closely monitored and/or reduced. Proximity to natural teeth presenting endodontic and/or periodontal lesions may result in implant contamination, but the influence of the type of edentulism on perio-pathogen presence is still unclear. These local conditions around an implant have a clear influence on peri-implant diseases development and progression, but there is still only limited evidence regarding their role as true risk indicators.

Analisis lesi endo-perio di periapikal melalui radiografi

Objectives: Endodontic lesions and periodontal lesions that appear together in the same tooth are called endo-perio lesions. This study is aimed to explain further on radiography characteristics of endo-perio lesions.
 Case Report: Case 1, A 21-year-old male patient came to RSGM with a lower left lower back pain complaint. The tooth was once cursed 1 year ago. In the radiographic picture there is a large radiolucent lesion on the alveolar bone around the distal root. Case 2, A 25-year-old female patient came to the Installation of Dental Conservation Specialist RSGM FKG Padjadjaran University complained that the lower left molar was sore and swollen gums had been 3 days. The tooth has been treated by a dentist in another city, but the treatment is not completed. Patients have taken the drug of mefenamic acid and amoxicillin each one grain.
 Conclusion: Periapical radiography is one of diagnostic imaging tools to help establish a more accurate diagnosis of endo-perio lesions. 

Treatment following extraction of teeth with periodontal–endodontic lesions: intact buccal bony wall

Treatment following extraction of teeth with periodontal–endodontic lesions: intact buccal bony wall

Treatment following extraction of teeth with periodontal–endodontic lesions: damaged buccal bony wall

In compromised teeth with periodontal–endodontic lesions, the decision to extract or maintain the teeth is complex while considering the endodontic, periodontal and reconstructive aspects of these teeth. Extraction of teeth with untreatable periodontal–endodontic lesions having severe alveolar bone damage can lead to difficulty in their surgical management. Various treatment approaches are available following the extraction of compromised teeth based on the patients’ risk profile, and clinical and radiographic evaluation.

Saliva and Serum Immune Responses in Apical Periodontitis.

Apical periodontitis is an inflammatory reaction at the apex of an infected tooth. Its microbiota resembles that of marginal periodontitis and may induce local and systemic antibodies binding to bacteria- and host-derived epitopes. Our aim was to investigate the features of the adaptive immune response in apical periodontitis. The present Parogene cohort (n = 453) comprises patients with cardiac symptoms. Clinical and radiographic oral examination was performed to diagnose apical and marginal periodontitis. A three-category endodontic lesion score was designed. Antibodies binding to the bacteria- and host-derived epitopes were determined from saliva and serum, and bacterial compositions were examined from saliva and subgingival samples. The significant ORs (95% CI) for the highest endodontic scores were observed for saliva IgA and IgG to bacterial antigens (2.90 (1.01–8.33) and 4.91 (2.48–9.71)/log10 unit), saliva cross-reacting IgG (2.10 (1.48–2.97)), serum IgG to bacterial antigens (4.66 (1.22–10.1)), and Gram-negative subgingival species (1.98 (1.16–3.37)). In a subgroup without marginal periodontitis, only saliva IgG against bacterial antigens associated with untreated apical periodontitis (4.77 (1.05–21.7)). Apical periodontitis associates with versatile adaptive immune responses against both bacterial- and host-derived epitopes independently of marginal periodontitis. Saliva immunoglobulins could be useful biomarkers of oral infections including apical periodontitis—a putative risk factor for systemic diseases.

Preterm birth associated with periodontal and dental indicators: a pilot case-control study in a developing country

Introduction: Preterm delivery is a multifactorial health problem that represents a serious public health problem around the world. In recent years, there has been an increase in scientific evidence suggesting associations between oral health status (mainly periodontal disease and tooth loss) and an increased risk of systemic diseases and various adverse pregnancy outcomes. This study explores the association between indicators of oral health and preterm delivery in a sample of Mexican pregnant women.Materials and methods: A case-control study was carried out with 111 pregnant (36 cases, 75 controls) who received prenatal care and delivered in an obstetric hospital in Pachuca, Mexico. Clinical files were reviewed to obtain the necessary information for the variables studied. The dependent variable was preterm delivery and the independent variables were gingivitis, periodontitis, DMFT index and its components, the number of decayed teeth with pulpal exposure or endodontic lesions, age of the mother, education, alcohol use, smoking status, number of gestations, and sex of the newborn.Results: The average ages were similar between the cases and the controls (24.29 ± 5.42 versus 24.89 ± 5.67, p = .5781). Significant differences were observed with gingivitis (p < .01) and periodontitis (p < .001). In addition, when the severity of gingivitis or periodontitis increased, the percentage of cases of preterm delivery increased (p < .01). The average number of teeth lost was higher among the cases than among the controls (1.33 ± 1.89 versus 0.81 ± 1.82, p < .05).Conclusions: It was found that gingivitis, periodontitis, and tooth loss were associated with preterm delivery. It is necessary to carry out actions aimed at the preservation of oral health in pregnant patients to avoid adverse results. These findings indicate a likely association, but it needs to be confirmed by large and well-designed studies.

Inspection of the Microbiota in Endodontic Lesions.

The primary objective of endodontic therapy is to create a biologically acceptable environment within the root canal system that allows for the healing and maintenance of the health of the peri-radicular tissue. Bacteria are one of the main causes of pulp problems, and they have different methods of penetrating and invading the endodontic space such as through carious lesions, traumatic pulp exposures, and fractures. The types of bacteria found range from facultative anaerobes to aerobes, up to the most resistant species able to survive in nutrient-free environments; the bacterial species Enterococcus faecalis belongs to this last group. Enterococcus faecalis is considered one of the main causes of recurring apical periodontal lesions following endodontic treatment, with persistent lesions occurring even after re-treatment. The review presented in this paper was performed in accordance with the PRISMA protocol and covers articles from the related scientific literature that were sourced from PubMed, Scopus, and Google Scholar using the following terms as keywords: “endodontic treatment”, “endodontic bacteria”, “microbial endodontic”, and “endodontic failure”. Only the articles considered most relevant for the purposes of this paper were read in full and taken into consideration for the following review. The results show that Enterococcus faecalis, Actinomycetes, and Propionibacterium propionicum are the species most frequently involved in persistent radicular and extra-radicular infections.

Outcome of non-surgical root canal treatment related to periodontitis and chronic disease medication among adults in age group of 60 years or more.

To assess the impact of non-endodontic factors like periodontitis and chronic disease medication (CDM) mostly affecting elderly people's health on the outcome of non-surgical root canal treatment (NSRCT). An increasing number of elderly people with high prevalence of marginal periodontitis and CDM benefit from adequate endodontic therapy, if irreversible pulpitis or apical periodontitis occurs. Only few data exist about the relevance of those non-endodontic factors on healing of endodontic lesions in a population 60years or more. Of 177 patients aged 60years or more with 212 NSRCTs performed between the year of 2010 and 2013, complete documentation was available for 112 teeth in 93 participants. Mean time between baseline and last follow-up was 38.93months. The primary endodontic factors studied were the periapical index (PAI) of periapical health, quality of the root canal filling and of coronal restoration, periodontal probing depth (PPD, mm) and tooth mobility (TM, 0-3). Secondary non-endodontic factors included the presence of marginal periodontitis and CDM, in particular antidiabetics, antihypertensives and anticoagulants. Statistical analyses were performed using Chi-square test statistics and logistic regression analysis. Periodontitis and CDM had no effect on endodontic outcome. Chronic intake of anticoagulants showed a significant association with endodontic outcome. Root-filled teeth with preoperative periapical lesions had a significantly higher rate of endodontic failure than those without preoperative lesion. The overall success rate of NSRCT was 87.1% with 81 healed teeth. Periodontitis and CDM have no impact on the endodontic outcome of NSRCT in a population 60years or more.

Elevated Systemic Inflammatory Burden and Cardiovascular Risk in Young Adults with Endodontic Apical Lesions

IntroductionThe aim of this study was to assess whether apical lesions are associated with inflammatory serum markers of cardiovascular risk, especially high-sensitivity C-reactive protein (hsCRP), in young adults. MethodsIn this cross-sectional study, otherwise healthy individuals with apical lesions of endodontic origin (ALEOs) and a clinical diagnosis of asymptomatic apical periodontitis and controls aged between 18 and 40 years were included. Patients’ sociodemographic characteristics, medical history, and classic cardiovascular risk factors were recorded, and the pathobiological determinants of atherosclerosis in youth score was calculated. Oral clinical and radiographic examinations were performed. Blood samples were collected to determine the lipid profile, glycated hemoglobin, hsCRP, immunoglobulin G, interleukin (IL)-6, IL-10, IL-12p70, matrix metalloproteinase 8, soluble vascular cellular adhesion molecule-1, soluble intercellular adhesion molecule-1, and soluble E-selectin. Bivariate and multivariate analyses adjusting for oral and classic cardiovascular risk factors were performed. ResultshsCRP levels were significantly higher in ALEO patients versus controls (median = 2.54 vs 0.78), whereas the pathobiological determinants of atherosclerosis in youth score was comparable among the groups. Also, the levels of IL-6, matrix metalloproteinase 8, and soluble E-selectin were significantly higher in ALEO patients. hsCRP, IL-6, and IL-12 correlated with soluble adhesion molecules. Bivariate analysis based on hsCRP serum concentrations ≥1 mg/L showed an odds ratio (OR) = 6.8, and the risk increased 3.3 times for an additional ALEO. In multivariate analysis, ALEO was significantly associated with hsCRP levels ≥1 mg/L (OR = 5.1–12.8) independently of the adjustment model. ALEO also associated with CRP levels >3 mg/L, which was significant after the adjustment for covariates (OR = 4.0). ConclusionsALEO is associated with the systemic inflammatory burden and cardiovascular risk determined by hsCRP, supporting a mechanistic link for cardiovascular diseases in young adults.

A rare case report of pyogenic granuloma associated with external root resorption

This is a rare case in which external root resorption was associated with localized gingival enlargement (pyogenic granuloma) in the upper right central incisor in a 49-year-old male clinically presenting with recession and mobility in other areas. The enlargement was pedunculated measuring 1.5 cm × 2 cm reddish pink in color, soft to fibrotic in consistency, and clinically diagnosed as pyogenic granuloma with chronic generalized periodontitis and endodontic lesion. Nonsurgical periodontal therapy was performed, enlargement was excised, and histopathological report was consistent with clinical report. Since it was associated with the cervical root resorption, the patient had to immediately undergo root canal treatment. The patient was observed for 4 months. The patient did not have any complaints, and the lesion was healed satisfactorily. For the esthetic purpose, gingival veneering was planned in the anterior region as there were root resorption and discoloration. After complete treatment, the gingiva is normal and healthy, and there was no sign of recurrence of the enlargement. The patient's periodontal condition is now routinely evaluated.

Pattern of Endodontic Periapical Lesion Extension in Anterior Teeth: A CBCT Study in an Iranian Population.

Health of periapical tissues has been considered as an index for the evaluation of endodontic outcomes. The present study sought to assess the pattern of periapical lesion extension in anterior teeth using cone-beam computed tomography (CBCT). In this descriptive study' 199 CBCT images belonged to patients aging from 15 to 79 were assessed according to periapical lesion extension in the regions of maxillary and mandibular anterior teeth. Maximum periapical lesion extensions in three orthogonal planes were measured and recorded in millimeters and were assessed according to age' gender' dental arch and tooth type. Statistical analysis was performed using percentages' repeated measure ANOVA and Bonferroni tests. The significant level was set at 0.05. The highest average of lesion extension, in both maxilla and mandible, was in vertical dimension' followed by horizontal buccolingual and horizontal mesiodistal dimensions' respectively. There were significant differences between the vertical and mesiodistal (P=0.004) and also mesiodistal and buccolingual (P=0.010) periapical lesion extension dimensions. In addition, there were significant differences in maxilla and mandible (P=0.012). In maxilla, there were no significant differences between the three tooth types (P=0.346) but in the mandibular arch, there were significant differences between central-canine (P=0.004) and lateral-canine (P=0.026). According to independent variables, only gender had a significant effect on the lesion extension in anterior regions of maxilla and mandible (P=0.001). The periapical lesion extensions were significantly higher in men compared with women. The bone destruction_as a consequence of periapical inflammatory process_ was greatest in the vertical, and lowest in the horizontal mesiodistal dimensions. That way, the extension in buccolingual dimension, which could not be detected in the 2-D imaging techniques, was rather high in the present study. Thus CBCT, as a 3-D imaging technique, could be recommended for the precise evaluation of lesion extension in the periapical area.

Capability of biodentine and the mineral trioxide aggregate mta sealing in furcal perforation repair. Literature review

Endodontic therapy seeks to maintain natural dentition's integrity in form function and aesthetics. Accidents during these procedures commonly occur which affect the prognosis of root canal treatment. A furcal perforation is a complication that refers to the mechanical or pathological communication between the pulp chamber and supporting ligament, in the lower area of the pulp chamber and leads to the worst result of the treatment. It can occur during the endodontic access or during the preparation of an intraradicular retainer, although it can also be due to caries lesions of root absorption. For long term success, perforations should be repaired as soon as possible with a biocompatible material any delay causes bacterial contamination and leads to complicated periodontal endodontic lesions. An ideal perforation repair material , should create an adequate seal, be biocompatible, not be affect by blood contamination, be a bactericide, radiopaque, induce bone formation and healing, induce mineralization, cementogenesis, facilite its manipulation and application. Various materials have been used to repair furcal perforations including MTA and Biodentine. The objective of this study is to carry out a review of the literature about the sealing capacity of MTA and Biodentine in the repair of furcal perforations. To reach this objective a bibliographic review is carried out in the leading odontological databases and magazines and articles are chosen according to their scientific validity their relationship with the topic and the year of publication wich stretches from 2009 to 2018.

Biomodification of compromised extraction sockets using hyaluronic acid and rhBMP-2: An experimental study in dogs.

This experimental study aims to evaluate the effect of hyaluronic acid on healing of infected extraction sockets compared with recombinant human bone morphogenetic protein-2 (rhBMP-2). Both third and fourth mandibular premolars of six beagle dogs were hemisected, and the distal roots were extracted at baseline. Subsequently, combined endodontic-periodontic lesions were induced at the remaining mesial roots. After 4months, the mesial roots on both sides of the mandible were removed. Four sockets per dog were randomly allocated to four groups: Group 1, Control; Group 2, only absorbable collagen sponge (ACS: carrier); Group 3, 1% hyaluronic acid (HA) gel + ACS; and Group 4, rhBMP-2 + ACS. After 3months of healing, the dogs were euthanized for microcomputed tomography and histologic analysis. After the lesion induction period (4months), communication between the periodontal lesion and endodontic periapical lesion was observed at all remaining mesial roots. Alveolar bone overgrowth was observed in groups 3 and 4, but bone volume density was not significantly different among all groups. At the crestal portion, mineralization, and osteocalcin expression were higher in groups 3 and 4 than in groups 1 and 2. Treatment with HA can promote bone formation and improve the wound healing rate comparable to rhBMP-2 in infected extraction sockets.

Streptococcus gordonii induces bone resorption by increasing osteoclast differentiation and reducing osteoblast differentiation

Streptococcus gordonii is commonly found in the periapical endodontic lesions of patients with apical periodontitis, a condition characterized by inflammation and periapical bone loss. Since bone metabolism is controlled by osteoclastic bone resorption and osteoblastic bone formation, we investigated the effects of S. gordonii on the differentiation and function of osteoclasts and osteoblasts. For the determination of bone resorption activity in vivo, collagen sheets soaked with heat-killed S. gordonii were implanted on mouse calvaria, and the calvarial bones were scanned by micro-computed tomography. Mouse bone marrow-derived macrophages (BMMs) were stimulated with M-CSF and RANKL for 2 days and then differentiated into osteoclasts in the presence or absence of heat-killed S. gordonii. Tartrate-resistant acid phosphatase staining was performed to determine osteoclast differentiation. Primary osteoblast precursors were differentiated into osteoblasts with ascorbic acid and β-glycerophosphate in the presence or absence of heat-killed S. gordonii. Alkaline phosphatase staining and alizarin red S staining were conducted to determine osteoblast differentiation. Western blotting was performed to examine the expression of transcription factors including c-Fos, NFATc1, and Runx2. Heat-killed S. gordonii induced bone destruction in a mouse calvarial implantation model. The differentiation of RANKL-primed BMMs into osteoclasts was enhanced in the presence of heat-killed S. gordonii. Heat-killed S. gordonii increased the expression of c-Fos and NFATc1, which are essential transcription factors for osteoclast differentiation. On the other hand, heat-killed S. gordonii inhibited osteoblast differentiation and reduced the expression of Runx2, an essential transcription factor for osteoblast differentiation. S. gordonii exerts bone resorptive activity by increasing osteoclast differentiation and reducing osteoblast differentiation, which may be involved in periapical bone resorption.

Potential Impact of Oral Inflammations on Cardiac Functions and Atrial Fibrillation.

Inflammation may be a risk factor for atrial fibrillation (AF). Oral infections frequently lead to chronic inflammation, such as gingivitis, periodontitis, and endodontic lesions. In this narrative review, we consider five basic pathogenic mechanisms that involve oral infections and inflammations in the pathogenesis of AF: (1) low level bacteremia by which oral bacteria enter the blood stream at inflamed sites of the oral cavity and invade the heart; (2) Systemic inflammation induced by inflammatory mediators, which are released from the sites of oral inflammation into the blood stream, affecting cardiac remodeling; (3) autoimmunity against molecular structures expressed in the heart caused by the host immune response to specific components of oral pathogens; (4) potentially arrhythmic effects mediated by activation of the autonomous nervous system triggered by oral inflammations; and (5) arrhythmic effects resulting from specific bacterial toxins that are produced by oral pathogenic bacteria. A number of studies support the involvement of all five mechanisms, suggesting a potentially complex contribution of oral inflammations to the pathogenesis of AF.

Roles of Oral Infections in the Pathomechanism of Atherosclerosis.

Oral infections occur frequently in humans and often lead to chronic inflammations affecting the teeth (i.e., caries), the gingival tissues surrounding the teeth (i.e., gingivitis and endodontic lesions), and the tooth-supporting structures (i.e., periodontitis). At least four basic pathogenic mechanisms have been proposed that involve oral inflammations in the pathogenesis of atherosclerosis: (1) low level bacteremia by which oral bacteria enter the blood stream and invade the arterial wall; (2) systemic inflammation induced by inflammatory mediators released from the sites of the oral inflammation into the blood stream; (3) autoimmunity to host proteins caused by the host immune response to specific components of oral pathogens; (4) pro-atherogenic effects resulting from specific bacterial toxins that are produced by oral pathogenic bacteria. In this narrative review, we summarize published experimental evidence related to these four mechanisms and discuss their impact on the pathogenesis of atherosclerosis.