Gaining more insight into the determinants of candida species pathogenicity in the oral cavity

Candida infection (candidiasis) is potentially life threatening and can occur in almost all anatomical sites, including the mouth. Candida species are in fact the most common fungal pathogens isolated from the oral cavity and frequently cause superficial infections such as oral candidiasis and denture-associated erythematous stomatitis. Whilst systemic dissemination of Candida from intraoral foci is rare and largely due to severe deficits of the host immune defenses, the development of localized oral candidiasis is most commonly related to a variety of non-immune determinants such as Candida virulence factors and permissive oral microenvironment. In particular, phenotypic switching and dental biofilm have emerged as major determinants for the pathogenicity of Candida and are currently the subject ofintense research. An understanding of the molecular aspects underlying the biological behavior of Candida will be the key to the development of effective preventive as well as therapeutic measures for invasive and oral candidiasis

Antimicrobial activity of ProRoot MTA in contact with blood

Dental materials based on Portland cement, which is used in the construction industry have gained popularity for clinical use due to their hydraulic properties, the interaction with tooth tissue and their antimicrobial properties. The antimicrobial properties are optimal in vitro. However in clinical use contact with blood may affect the antimicrobial properties. This study aims to assess whether antimicrobial properties of the Portland cement-based dental cements such as mineral trioxide aggregate (MTA) are also affected by contact with blood present in clinical situations. ProRoot MTA, a Portland cement-based dental cement was characterized following contact with water, or heparinized blood after 1 day and 7 days aging. The antimicrobial activity under the mentioned conditions was assessed using 3 antimicrobial tests: agar diffusion test, direct contact test and intratubular infection test. MTA in contact with blood was severely discoloured, exhibited an additional phosphorus peak in elemental analysis, no calcium hydroxide peaks and no areas of bacterial inhibition growth in the agar diffusion test were demonstrated. ProRoot MTA showed limited antimicrobial activity, in both the direct contact test and intratubular infection test. When aged in water ProRoot MTA showed higher antimicrobial activity than when aged in blood. Antimicrobial activity reduced significantly after 7 days. Further assessment is required to investigate behaviour in clinical situations.ERDF (Malta) for the financing of the testing equipment through the project: “Developing an Interdisciplinary Material Testing and Rapid Prototyping R&D Facility” (Ref. no. 012)

PRISMA for abstracts: best practice for reporting abstracts of systematic reviews in Endodontology

An abstract is a brief overview of a scientific, clinical or review manuscript as well as a stand‐alone summary of a conference abstract. Scientists, clinician–scientists and clinicians rely on the summary information provided in the abstracts of systematic reviews to assist in subsequent clinical decision‐making. The Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) for Abstracts checklist was developed to improve the quality, accuracy and completeness of abstracts associated with systematic reviews and meta‐analyses. The PRISMA for Abstracts checklist provides a framework for authors to follow, which helps them provide in the abstract the key information from the systematic review that is required by stakeholders. The PRISMA for Abstracts checklist contains 12 items (title, objectives, eligibility criteria, information sources, risk of bias, included studies, synthesis of results, description of the effect, strength and limitations, interpretation, funding and systematic review registration) under six sections (title, background, methods, results, discussion, other). The current article highlights the relevance and importance of the items in the PRISMA for Abstracts checklist to the specialty of Endodontology, while offering explanations and specific examples to assist authors when writing abstracts for systematic reviews when reported in manuscripts or submitted to conferences. Strict adherence to the PRISMA for Abstracts checklist by authors, reviewers and journal editors will result in the consistent publication of high‐quality abstracts within Endodontology

A Micro-Computed Tomography Study of the Root Canal Morphology of Mandibular First Premolars in an Emirati Population

ObjectiveTo investigate variations in the root canal morphology of mandibular first premolars in a population from the United Arab Emirates using micro-computed tomography (micro-CT) and conventional radiography.Materials and methodsThree-dimensional images of 50 extracted human mandibular first premolars were produced using a micro-CT scanner, and conventional radiography was also used to record the number of roots, the root canal system configuration, the presence of a C-shaped canal system and lateral canals, intercanal communications, and the number and location of apical foramina. The interpretations of micro-CT and conventional radiography were statistically analyzed using Fisher's exact test.ResultsVariable root canal configurations based on Vertucci's classification were observed in the teeth (i.e., types I, III, IV, V, and VII). The examined teeth exhibited the following 2 additional root canal configurations, which did not fit Vertucci's classification: type 1-2-3 and type 1-3. A C-shaped canal configuration was present in 14 (28%) cases, and lateral canals were present in 22 (44%) cases. Apical deltas were found in 25 (50%) cases, intercanal communications were seen in 6 (12%) cases, and apical loops were seen in 2 (4%) of the samples. Micro-CT and X-ray imaging identified 39 (78%) and 34 (68%) apical foramina, respectively. A single apical foramen was detected in 33 (66%) samples, and 2 or 3 apical foramina were detected in 14 (28 %) and 3 (6%) samples, respectively. In 18.5 (37%) samples the apical foramina were located centrally, and in 31 (62%) they were located laterally.ConclusionA complex morphology of the mandibular first premolars was observed with a high prevalence of multiple root canal systems

A Micro-Computed Tomography Study of the Root Canal Morphology of Mandibular First Premolars in an Emirati Population

ObjectiveTo investigate variations in the root canal morphology of mandibular first premolars in a population from the United Arab Emirates using micro-computed tomography (micro-CT) and conventional radiography.Materials and methodsThree-dimensional images of 50 extracted human mandibular first premolars were produced using a micro-CT scanner, and conventional radiography was also used to record the number of roots, the root canal system configuration, the presence of a C-shaped canal system and lateral canals, intercanal communications, and the number and location of apical foramina. The interpretations of micro-CT and conventional radiography were statistically analyzed using Fisher's exact test.ResultsVariable root canal configurations based on Vertucci's classification were observed in the teeth (i.e., types I, III, IV, V, and VII). The examined teeth exhibited the following 2 additional root canal configurations, which did not fit Vertucci's classification: type 1-2-3 and type 1-3. A C-shaped canal configuration was present in 14 (28%) cases, and lateral canals were present in 22 (44%) cases. Apical deltas were found in 25 (50%) cases, intercanal communications were seen in 6 (12%) cases, and apical loops were seen in 2 (4%) of the samples. Micro-CT and X-ray imaging identified 39 (78%) and 34 (68%) apical foramina, respectively. A single apical foramen was detected in 33 (66%) samples, and 2 or 3 apical foramina were detected in 14 (28 %) and 3 (6%) samples, respectively. In 18.5 (37%) samples the apical foramina were located centrally, and in 31 (62%) they were located laterally.ConclusionA complex morphology of the mandibular first premolars was observed with a high prevalence of multiple root canal systems

Gaining More Insight into the Determinants of Species Pathogenicity in the Oral Cavity

Candida infection (candidiasis) is potentially life threatening and can occur in almost all anatomical sites, including the mouth. Candida species are in fact the most common fungal pathogens isolated from the oral cavity and frequently cause superficial infections such as oral candidiasis and denture-associated erythematous stomatitis. Whilst systemic dissemination of Candida from intraoral foci is rare and largely due to severe deficits of the host immune defenses, the development of localized oral candidiasis is most commonly related to a variety of non-immune determinants such as Candida virulence factors and permissive oral microenvironment. In particular, phenotypic switching and dental biofilm have emerged as major determinants for the pathogenicity of Candida and are currently the subject of intense research. An understanding of the molecular aspects underlying the biological behavior of Candida will be the key to the development of effective preventive as well as therapeutic measures for invasive and oral candidiasis

A Role of Oral Bacteria in Bisphosphonate-induced Osteonecrosis of the Jaw

No consensus has yet been reached to associate oral bacteria conclusively with the etio-pathogenesis of bisphosphonate-induced osteonecrosis of the jaw (BONJ). Therefore, the present study examined the effects of oral bacteria on the development of BONJ-like lesions in a mouse model. In the pamidronate (Pam)-treated mice, but not control non-drug-treated mice, tooth extraction followed by oral infection with Fusobacterium nucleatum caused BONJ-like lesions and delayed epithelial healing, both of which were completely suppressed by a broad-spectrum antibiotic cocktail. Furthermore, in both in vitro and in vivo experiments, the combination of Pam and Fusobacterium nucleatum caused the death of gingival fibroblasts (GFs) and down-regulated their production of keratinocyte growth factor (KGF), which induces epithelial cell growth and migration. Therefore, in periodontal tissues pre-exposed to bisphosphonate, bacterial infection at tooth extraction sites caused diminished KGF expression in GFs, leading to a delay in the epithelial wound-healing process that was mitigated by antibiotics