Abstract There are many restrictions on topical medications for the oral cavity. Various factors affect the topical application of drugs in the oral cavity, an open and complex environment. The complex physical and chemical environment of the oral cavity, such as saliva and food, will influence the effect of free drugs. Therefore, drug delivery systems have served as supporting structures or as carriers loading active ingredients, such as antimicrobial agents and growth factors (GFs), to promote antibacterial properties, tissue regeneration, and engineering for drug diffusion. These drug delivery systems are considered in the prevention and treatment of dental caries, periodontal disease, periapical disease, the delivery of anesthetic drugs, etc. These carrier materials are designed in different ways for clinical application, including nanoparticles, hydrogels, nanofibers, films, and scaffolds. This review aimed to summarize the advantages and disadvantages of different carrier materials. We discuss synthesis methods and their application scope to provide new perspectives for the development and preparation of more favorable and effective local oral drug delivery systems.

ABSTRACT Objective: Enterococcus faecalis is the dominant microbial species responsible for persistent apical periodontitis with ability to deeply penetrate into the dentin. Exopolysaccharides (EPS) contribute to the pathogenicity and antibiotic resistance of E. faecalis. Our aim was to investigate the antimicrobial activity of calcium hydroxide (CH), camphorated parachlorophenol (CMCP), and chlorhexidine (CHX) against E. faecalis in dentinal tubules. Material and Methods: Decoronated single-canal human teeth and semicylindrical dentin blocks were incubated with E. faecalis for 3 weeks. Samples were randomly assigned to six medication groups for 1 week (n=10 per group): CH + 40% glycerin-water solution (1:1, wt/vol); CMCP; 2% CHX; CH + CMCP (1:1, wt/vol); CH + CMCP (2:3, wt/vol); and saline. Bacterial samples were collected and assayed for colony-forming units. After dentin blocks were split longitudinally, confocal laser scanning microscopy was used to assess the proportion of viable bacteria and EPS production in dentin. Results: CMCP exhibited the best antimicrobial activity, while CH was the least sensitive against E. faecalis (p<0.05). CHX showed similar antimicrobial properties to CH + CMCP (1:1, wt/vol) (p>0.05). CH combined with CMCP inhibited EPS synthesis by E. faecalis, which sensitized biofilms to antibacterial substances. Moreover, increasing concentrations of CMCP decreased EPS matrix formation, which effectively sensitized biofilms to disinfection agents. Conclusion: The EPS matrix dispelled by CH paste with CMCP may be related to its bactericidal effect; the visualization and analysis of EPS formation and microbial colonization in dentin may be a useful approach to verify medicaments for antimicrobial therapy.

ABSTRACTPurpose:To evaluate the clinical value of computed tomography angiography (CTA) in reducing the risk of hemorrhage associated with mini-percutaneous nephrolithotomy (PCNL).Materials and Methods:A total of 158 patients with renal or ureter stones who had undergone mini-percutaneous nephrolithotomy were retrospectively enrolled into this study from May of 2011 to April of 2014. Group 1 (65 patients) underwent computed tomography angiography, and Group 2 (93 patients) underwent non-contrast CT. The clinical characteristics of the patients and hemorrhagic complications were recorded. The hematologic complications (transfusion rate, and preoperative and postoperative hemoglobin values) were assessed.Results:There were no statistically significant differences in age, body mass index(BMI), stone diameter, operative time, stone-free rate, and hospital stay between the 2 groups. In group 2, 1 patient (1.1%) developed a renal arteriovenous fistula and was treated with embolus therapy. In addition, Group 2 showed significantly drop in hemoglobin (3.6 g/dL vs. 2.4 g/dL, respectively; P <0.001) and more transfusions (9.7% vs. 1.5%, respectively; P <0.05) compared with Group 1.Conclusion:The study showed that patients who underwent computed tomography angiography prior to percutaneous nephrolithotomy had lower drop of hemoglobin and needed less transfusions. These findings may suggest that the use of computed tomography angiography may reduce the risk of bleeding during percutaneous nephrolithotomy.

Alveolar bone dehiscences, which were "V" shaped defects related the margin of the alveolar bone, were common findings in different populations and decreased bony support of teeth. It was difficult to detect dehiscence during direct clinical examination. All of the previous studies on the prevalence of dehiscences were based on dry human skulls. In the current article, we evaluated the prevalence of dehiscences occurring naturally in a Chinese subpopulation, and prepared a classification of dehiscences using cone-beam computed tomography (CBCT). The high prevalence rate of dehiscences and different characteristics of each category suggest that it would be helpful for clinicians who perform periodontal surgery, endodontic surgery, implant surgery or orthodontic treatment to understand which teeth are most often associated with such bony defects, and to consider the effect of severe dehiscences on their diagnosis and treatment plan.

Las dehiscencias óseas alveolares, con forma de "V" en el margen del hueso alveolar, son hallazgos comunes en diferentes poblaciones y provocan una disminución del soporte óseo de los dientes. La dehiscencia fue difícil de identificar durante la exploración clínica directa. Todos los estudios anteriores sobre la prevalencia de dehiscencia se basaron en cráneos humanos secos. En el presente artículo, se evaluó la prevalencia de dehiscencia natural ocurrido en una subpoblación de China. Realizamos una clasificación de las dehiscencias mediante tomografía computarizada cone-beam (TCCB). La alta prevalencia de dehiscencias y las diferentes características de cada categoría sugieren que esta clasificación sería de gran ayuda para los médicos que realizan cirugía periodontal, endodóntica, cirugía de implantes o tratamiento de ortodoncia, permitiendo informar sobre que dientes están más frecuentemente asociados con tales defectos óseos, y poder considerar los efectos severos de las dehiscencias severas en el diagnóstico y el plan de tratamiento.

Irregular root configurations which often challenge the requirements of successful root canal treatments are always misleading doctors to incorrect clinical judgments and treatment planning. In this article we describe a rare case of CBCT C-shaped mandibular premolar with a huge area of invagination measuring 6 mm ´ 3 mm, which we termed a "radicular rift valley" from a 76-year-old man. Considering the complex process of differential diagnosis, the overall status of disease condition and the will of the patient we proposed five treatment plans and finally conservatively chose plan B composed of both RCT and periapical scaling. A related literature review is also added into this article to describe the whole situation of root invagination, to stress the importance of the vigilance of diagnosis and to provide reference views for future similar diseases.

Las configuraciones radiculares irregulares que a menudo desafían las exigencias de un tratamiento de canal radicular exitoso, son siempre engañosas llevando al especialista a juicios clínicos y planificación de tratamientos erróneos. En este artículo se describe, en un hombre de 76 años de edad, un raro caso de un premolar mandibular que mediante CBCT se observa la forma de C con un área enorme de invaginación midiendo 6 mm x 3 mm, lo que hemos denominado un "Rift valley radicular ". Teniendo en cuenta el complejo proceso de diagnóstico diferencial, el estado general de enfermedad y la voluntad del paciente, se propusieron cinco planes de tratamiento y, finalmente, se eligió el plan B conservador compuesto por el tratamiento del canal radicular y tratamiento periapical. Una revisión de la literatura relacionada se añade en este artículo para describir las situación de invaginación radicular, haciendo hincapié en la importancia del diagnóstico y para proporcionar referencias para enfermedades similares futuras.