Phages in a thermoreversible sustained-release formulation targeting E. faecalis in vitro and in vivo.

INTRODUCTION: Enterococcus faecalis is a key pathogen recovered from root canals when conventional treatment fails. Phage therapy has generated new interest in combating pathogens. A sustained-release formulation using specific phages against E. faecalis may offer an alternative approach. OBJECTIVES: To evaluate the efficacy of anti-E. faecalis phages formulated in a thermo- sustained-release system against E. faecalis in vitro and in vivo. METHODS: EFDG1 and EFLK1 phages were formulated with poloxamer P407. Gelation time, phage survival, activity and toxicity were evaluated. Lytic activity was evaluated in vitro against E. faecalis at various growth phases, including anti-biofilm activity. Methods included viable bacterial count (CFU/mL), biofilm biomass determination and electron microscopy (live/dead staining). Further evaluation included infected incisors in an in vivo rat model. Anti-E. faecalis phage-cocktail suspension and sustained-release phage formulation were evaluated by viable bacterial count (CFU/mL), histology, scanning electron microscopy (SEM) and 16S genome sequencing of the microbiota of the root canal. RESULTS: Gelation time for clinical use was established. Low toxicity and a high phage survival rate were recorded. Sustained-release phages reduced E. faecalis in logarithmic (4 logs), stationary (3 logs) and biofilm (4 logs) growth phases. Prolonged anti-biofilm activity of 88% and 95% reduction in biomass and viable counts, respectively, was recorded. Reduction of intracanal viable bacterial counts was observed (99% of enterococci) also seen in SEM. Phage treatment increased Proteobacteria and decreased Firmicutes. Histology showed reduced periapical inflammation and improved healing following phage treatment. CONCLUSION: Poloxamer P407 formulated with phages has an effective and long-lasting effect in vitro and in vivo targeting E. faecalis.

PLGA submicron particles containing chlorhexidine, calcium and phosphorus inhibit Enterococcus faecalis infection and improve the microhardness of dentin.

Enterococcus faecalis (E. faecalis), a Gram-positive facultative anaerobe, is reported to take responsibility for a large portion of refractory root canal infections and root canal re-infections of human teeth. Chlorhexidine is a strong bactericide against E. faecalis but cannot infiltrate into dentinal tubules. On the other hand, a common negative effect of root canal medicaments is the decrease of dentin microhardness. In this study, poly(D,L-lactic-co-glycolide) (PLGA) submicron particles were applied as delivery carriers to load and release the chlorhexidine as well as calcium and phosphorus. The release profiles, antibacterial ability against E. faecalis, infiltration ability into dentinal tubules, biocompatibility and effects on dentin microhardness of these particles were investigated. Results revealed that encapsulated chemicals could be released in a sustained manner from the particles. The particles also exhibited excellent biocompatibility on MC3T3-E1 cells and significant antimicrobial property against E. faecalis. On dentin slices, the particles could be driven into dentinal tubules by ultrasonic activiation and inhibit E. faecalis colonization. Besides, dentin slices medicated with the particles displayed an increase in microhardness. In conclusion, PLGA submicron particles carrying chlorhexidine, calcium and phosphorus could be developed into a new intra-canal disinfectant for dental treatments.

Influencia de tomografías de haz cónico en el plan de tratamiento de endodoncia en casos de elevado grado de dificultad / The influence of cone-beam computed tomographies on endodontic treatment planning in highly difficult cases

Introducción: el diagnóstico en endodoncia incorporó los estudios de tomografías de haz cónico (CBCT). Esnecesario entender el alcance y la utilidad de estos para saber cuándo solicitarlos. Objetivos: el objetivo de este estudio fue determinar la indicación de CBCT previa al tratamiento endodóntico y su relación con el nivel de dificultad del caso atratar. Métodos: se seleccionaron al azar 15 casos clínicos de alta dificultad derivados a tratamiento de endodoncia.Se realizó diagnóstico clínico y radiográfico. Se estimaron los recursos necesarios para el tratamiento con unformulario diseñado para ello. Se solicitó un estudio de CBCT. Una vez obtenido el estudio, el mismoprofesional que realizó el diagnóstico clínico navegó el software de visualización y llenó nuevamente el formulario. Fueron comparados los formularios previos y posteriores a las CBCT. Se establecieron las diferencias encontradas entre ellos. Resultados: todos los casos analizados tuvieron diferencias en la comparación entre los formularios. Conclusiones: el uso de CBCT en los casos de elevada dificultad permite un diseño de plan de tratamiento más preciso.

Introduction: the endodontic diagnosis includes the study of cone beam tomography (CBCT). It is necessary to understand the scope and usefulness of CBCTto know when to request it.Objectives: the aim of this study was to determine the requirement of CBCT before endodontic treatment and its connection with the level of difficulty that the case presents. Methods: 15 endodontic cases of high difficulty were taken randomly. Clinical and radiographic diagnosis was made. The necessary resourcesfor the treatment were estimated according to aspecially designed form. A CBCT study was request. Once the study was obtain, the same professionalwho performed the clinical diagnosis browsed the software to read CBCT results and filled a new form.Both CBCT forms need to be compared to establish differences between them. Results: all the cases analysed were compare, andshowed differences between the two forms. Conclusion: the use of CBCT in high difficult cases provides a more accurate design of the treatment plans.

[Endodontic treatment efficacy enhancement by means of instrumental physiotherapy]. / Povyshenie éffektivnosti éndodonticheskogo lecheniia s pomoshch'iu apparaturnykh metodov.

The article describes in detail and examines the prospects of such methods as electroodontodiagnosis, diathermocoagulation and apex-phoresis. It proves the necessity of development and standardization of devices for the mentioned treatment modalities that will improve the effectiveness an quality of caries complications treatment.

Critical Review on Eliminating Endodontic Dental Infections Using Herbal Products.

The main purpose of a root canal treatment is to eliminate the bacteria and their products from the pulp space. Chemomechanical preparation (chemical-refers to irrigating solutions, i.e., either synthetic chemicals or herbal solutions and mechanical-refers to instrumentation of a root canals with endodontic files) of a root canal system plays a major role in obtaining the rationale of root canal treatment. Various synthetic chemicals known as endodontic irrigants play a major role in disinfection, but also have undesirable properties like allergic potential, toxicity, unacceptable taste, etc. Today there is a major change in trend towards the use of natural herbal medicines as a part of dental treatment due to its easy availability, less toxicity, and cost effectiveness. This article aims to provide a comprehensive review of various herbal endodontic irrigants evaluated for their effectiveness in the disinfection of a root canal system. This literature review is conducted using electronic databases "PubMed," "Google Scholar," and "Scopus," and articles were limited to those in the English language and published between 1980 and 2014.

A comparative evaluation of antibacterial effectiveness of sodium hypochlorite, Curcuma longa, and Camellia sinensis as irrigating solutions on isolated anaerobic bacteria from infected primary teeth.

CONTEXT: In endodontics, most of the commercial intra-canal medicaments have cytotoxic reactions and because of their inability to eliminate bacteria from dentinal tubules, recent medicine has turned its attention to the usage of biologic medication prepared from natural plants. The literature to testify the efficacy of natural alternatives in primary teeth is meagre and its effects as irrigating solutions need to be evaluated. AIM: To evaluate the antibacterial effectiveness of sodium hypochlorite, ethanolic extracts of Curcuma longa (turmeric) and Camellia sinensis (green tea) as irrigating solutions against the anaerobic bacteria isolated from the root canals of infected primary teeth. MATERIALS AND METHODS: Thirty patients were selected based on the selected inclusion and exclusion criteria. Preoperative radiographs were taken. Rubber dam isolation and working length estimation were done, following which thirty samples were taken from the root canals of infected primary teeth using sterile absorbent paper points and transferred to tubes containing thioglycolate transport medium. The bacteria were then isolated using standard microbiological protocols and were subjected to antibiotic sensitivity testing using the three test irrigants. STATISTICAL ANALYSIS: SPSS 18 software using Chi-square test was used for statistical analysis. RESULTS: The most commonly isolated bacteria included Porphyromonas sp., Bacteroides fragilis, Peptostreptococcus, and Staphylococcus aureus. Sodium hypochlorite and C. longa (turmeric) showed good antibacterial effect and were effective against most of the isolated bacteria. There was statistically significant difference in the antibacterial effect among the three tested groups (P < 0.001). The least effective was C. sinensis (green tea). CONCLUSION: The infected primary teeth almost always present with a polymicrobial structure with a wide variety of anaerobic bacteria. The chemo-mechanical preparation plays an important role in eradicating the population of predominant micro-organisms in treating these teeth with promising effects with the use of newer test irrigants while avoiding the side effects of sodium hypochlorite.

A Randomized Trial Using 3Mixtatin Compared to MTA in Primary Molars with Inflammatory Root Resorption: A Novel Endodontic Biomaterial.

OBJECTIVES: Novel methods for preserving primary teeth can help to maintain their developmental, esthetic, and functional capabilities. The aim of this study was to assess the success of the repair of bony defects, caused by pre-treatment perforations, with a mixture of three antibiotics combined with simvastatin (3Mixtatin) compared to MTA in hopeless primary molars. STUDY DESIGN: In this randomized clinical trial, 80 teeth from 65 healthy children aged 3-6 years with interradicular or periapical root resorption and/or perforation in primary molars were treated either with 3Mixtatin or MTA before conventional pulpectomy and restoration. The subjects were followed up clinically and radiographically for 4, 6, 12 and 24 months after pulp treatment to evaluate and compare the healing process. The data were compared using chi-square test at a significance level of 0.05. RESULTS: By the end of 24 months in 3Mixtatin group, 31 (96.8%) teeth revealed no clinical signs or symptoms with arrested resorption progress in radiographs. In MTA group, clinical signs and symptoms including pain, mobility and sinus tract were observed in 18 (48.6%) teeth with cessation of root/interradicular radiolucency in 7 (18.9%) teeth without bone repair. CONCLUSIONS: Radiographic and clinical healing occurred more successfully following 3Mixtatin treatment compared to treatment with MTA, it may lead to a paradigm shift in the pulpal treatment of primary teeth in the future.

Nigella sativa and its active constituent thymoquinone in oral health.

In this review, we summarized published reports that investigated the role of Nigella sativa (NS) and its active constituent, thymoquinone (TQ) in oral health and disease management. The literature studies were preliminary and scanty, but the results revealed that black seed plants have a potential therapeutic effect for oral and dental diseases. Such results are encouraging for the incorporation of these plants in dental therapeutics and hygiene products. However, further detailed preclinical and clinical studies at the cellular and molecular levels are required to investigate the mechanisms of action of NS and its constituents, particularly TQ.

The expression of hyperpolarization-activated cyclic nucleotide-gated channel 1 (HCN1) and HCN2 in the rat trigeminal ganglion, sensory root, and dental pulp.

Hyperpolarization-activated cyclic nucleotide-gated channel 1 (HCN1) and 2 (HCN2) are abundantly expressed in primary sensory neurons and contribute to neuronal excitability and pathological pain. We studied the expression of HCN1 and HCN2 in the rat trigeminal ganglion (TG) neurons and axons in the dental pulp, and the changes in their expression following inflammation, using light- and electron-microscopic immunocytochemistry and quantitative analysis. HCN1 and HCN2 were expressed predominantly in large-sized, neurofilament 200-immunopositive (+) or parvalbumin+ soma in the TG whereas they were expressed mostly in unmyelinated and small myelinated axons in the sensory root. The expression was particularly strong along the plasma membrane in the soma. In the dental pulp, majority of HCN1+ and HCN2+ axons coexpressed calcitonin gene-related peptide. They were expressed mainly in the peripheral pulp and pulp horn where the axons branch extensively in the dental pulp. The expression of HCN1 and HCN2 in TG neurons increased significantly in rats with experimentally induced inflammation of the dental pulp. Our findings support the notion that HCN1 and HCN2 are expressed mainly by both the soma of mechanosensitive neurons in the TG and peripheral axons of nociceptive neurons in the sensory root, and may play a role in the mechanisms of inflammatory pain from the dental pulp.

Pulp development, repair, and regeneration: challenges of the transition from traditional dentistry to biologically based therapies.

The traditional concept of replacing diseased tooth/pulp tissues by inert materials (restoration) is being challenged by recent advances in pulp biology leading to regenerative strategies aiming at the generation of new vital tissue. New tissue formation in the pulp chamber can be observed after adequate infection control and the formation of a blood clot. However, differentiation of true odontoblasts is still more speculative, and the approach is largely limited to immature teeth with open apices. A more systematic approach may be provided by the adoption of the tissue engineering concepts of using matrices, suitable (stem) cells, and signaling molecules to direct tissue events. With these tools, pulplike constructs have already been generated in experimental animals. However, a number of challenges still remain for clinical translation of pulp regeneration (eg, the cell source [resident vs nonresident stem cells, the latter associated with cell-free approaches], mechanisms of odontoblast differentiation, the pulp environment, the role of infection and inflammation, dentin pretreatment to release fossilized signaling molecules from dentin, and the provision of suitable matrices). Transition as a process, defined by moving from one form of "normal" to another, is based not only on the progress of science but also on achieving change to established treatment concepts in daily practice. However, it is clear that the significant recent achievements in pulp biology are providing an exciting platform from which clinical translation of dental pulp regeneration can advance.

Osteogenesis imperfecta and pneumatization of bone-- a hidden reality.

Osteogenesis imperfecta is a bone disorder in which three factors that influence bone strength (quality, mass, and geometry of osseous tissue) are affected. Pneumatization refers to the development of air-filled cavities inside the bone. Knowledge about these air-filled cavities provides valuable information for understanding the diagnosis and spread of various pathologic entities like hemangiomas, giant cell tumors, eosinophilic granulomas, and even metastatic tumor deposits. This paper presents a case in which radiologic, clinical, biochemical, and karyotypic evaluations lead to a diagnosis of osteogenesis imperfecta.

Efficacy of bacteriophage treatment on Pseudomonas aeruginosa biofilms.

INTRODUCTION: Bacterial viruses (phages) have been used successfully in the treatment of animal and human bacterial infections. This study examined the potential use of phage therapy against Pseudomonas aeruginosa strain PA14 biofilms in a root canal model. METHODS: Part 1: The 24-hour and 96-hour PA14 biofilms grown in microplates were treated with phages identified as possessing potential biofilm-degrading activities, and the post-treatment bacterial biomass was quantified by using crystal violet staining. Part 2: The 24-hour and 96-hour PA14 biofilms grown in prepared root canals of extracted human mandibular incisors were treated with phages identified with potential biofilm-degrading activities. Post-treatment intracanal samples were taken by using paper points and round burs to assess phage and bacterial counts. RESULTS: Part 1: We identified 2 phages (JBD4 and JBD44a) with putative biofilm-degrading activities. Treatment of PA14 biofilms with these phages produced a significant reduction in the mean percentage of biomass in 24-hour (P< .05) and 96-hour (P= .08) biofilms. Part 2: In 24-hour and 96-hour PA14 biofilms in a root canal model, no significant difference was found in the number of colony-forming units after phage treatment (P> .05). CONCLUSIONS: Phage application significantly reduced the biomass of 24-hour and 96-hour PA14 biofilms grown on microplates but did not produce significant reduction of 24-hour or 96-hour PA14 biofilms grown in the extracted tooth model.

In vitro evaluation of MTAD and nisin in combination against common pathogens associated with root canal infection.

INTRODUCTION: Many pathogenic microorganisms were found in an infected root canal. The object of this study was to evaluate the effect of MTAD in combination with nisin on the pathogens associated with root canal infection. METHODS: The survival rates of 9 pathogenic bacteria were determined after 1-, 5-, and 10-minute treatment with MTAD, MTAN (substitution of doxycycline with nisin), and MTADN (nisin in combination with doxycycline). The survival rates of Enterococcus faecalis in the starvation phase and pretreatment alkalization as well as in the normal physiological state under MTAD, MTAN, and MTADN challenge for 1, 5, and 10 minutes were evaluated and compared. Furthermore, scanning electron microscopy was used to observe the morphologic modification of Actinomyces naeslundii, Lactobacillus paracasei, and Porphyromonas gingivalis after MTAD and MTADN treatment. RESULTS: L. fermenti, L. paracasei, A. viscosus, A. naeslundii, Streptococcus gordonii, and Peptostreptococcus were more sensitive to MTADN and MTAN than to MTAD. MTAD, MTAN, and MTADN showed a rapid antibacterial effect on P. gingivalis, Prevotella intermedia, and Fusobacterium nucleatum. Enterococcus faecalis in the stress state was as sensitive to MTAD, MTAN, and MTADN as the control E. faecalis. Furthermore, in the observation of scanning electron microscopy, the membranes in A. naeslundii and L. paracasei presented significant rupture, and P. gingivalis did not exhibit significant damage after MTADN treatment. CONCLUSIONS: MTAD in combination with nisin improved antibacterial efficacy against pathogens, especially for some gram-positive bacteria associated with persistent intracanal infection. Therefore, the combination had the potential to be used as an effective intracanal irrigation.

Endodontic application of cone-beam computed tomography in South Korea.

INTRODUCTION: This study aimed to investigate the incidence of cone-beam computed tomography (CBCT) associated with endodontic procedures during 2009 in South Korea and to retrospectively evaluate information from CBCT with large field of view (FOV), which is popular in South Korea. METHODS: The Health Insurance Review and Assessment agency, which reviews all medical and dental expenses covered under the Korean National Health Insurance (NHI) system, was queried for data on the nationwide number of CBCTs associated with some treatment procedures. To compare digital periapical radiography and CBCT retrospectively, 470 roots of 257 root canal-infected teeth were enrolled. RESULTS: In total, 13,209 cases of NHI-covered CBCT were performed in South Korea during 2009, excluding cases for implant restoration and orthodontics. In total, 1253 and 95 CBCT cases were combined with root canal length measuring and apicoectomy, respectively. In a retrospective comparison, CBCT with large FOV provided more information about the presence of apical periodontitis, distortion of cortical bone, and identification of root compared with digital periapical radiography. CONCLUSIONS: CBCT with large FOV is useful in nonsurgical endodontic treatment and provides more information compared with digital periapical radiography.

Reversal of soft-tissue anesthesia in asymptomatic endodontic patients: a preliminary, prospective, randomized, single-blind study.

INTRODUCTION: Phentolamine has been reported to be an effective local anesthetic reversal agent for soft tissue but has not been studied in endodontics. The purpose of this preliminary, prospective, randomized, single-blind study was to evaluate the reversal of soft-tissue anesthesia using phentolamine in asymptomatic endodontic patients. METHODS: Eighty-five adult subjects having a maxillary or mandibular asymptomatic tooth requiring endodontic therapy received either phentolamine or sham treatment(s) at the end of the endodontic treatment appointment. Soft-tissue anesthesia was monitored by subjects every 15 minutes for 5 hours. Subjects reported postoperative injection site pain and tooth pain using a Heft-Parker visual analog score every 30 minutes for the first 2 postoperative hours and every hour for 3 hours. RESULTS: There was a statistically significant difference in time to return-to-normal sensation for the maxillary lip/cheek and mandibular lip. Subjects who received phentolamine experienced an 88-minute decrease in time to return-to-normal maxillary lip/cheek sensation and a 47-minute decrease in time to return-to-normal mandibular lip sensation. The administration of phentolamine was not significantly more painful than administration of a sham treatment, and patients who received phentolamine did not experience significantly more postoperative pain at the injection site. Postoperative complications were minimal, and no clinically significant adverse reactions to the phentolamine were reported. CONCLUSIONS: Phentolamine would be beneficial for asymptomatic endodontic patients who would like to experience a faster return-to-normal soft-tissue function and sensation after the administration of local anesthesia.

Pulp pathosis in inlayed teeth of the ancient Mayas: a microcomputed tomography study.

AIM: To evaluate three-dimensionally, using microcomputed tomography (µCT), the anatomical relationship between the cavity prepared to hold the inlay stone and the pulp chamber in the teeth of the ancient Maya. METHODOLOGY: Six well-preserved teeth from Maya corpses found in an archaeological site in Guatemala (approximately 1600 year old) were selected and scanned using a high-resolution µCT system (SkyScan 1174v2; SkyScan N.V., Kontich, Belgium). The sample comprised six maxillary teeth: two canines, one premolar, two central incisors and one lateral incisor. All teeth had one or two inlay stones on the buccal surface of the crown. Each specimen was scanned at an isotropic resolution of 22.5 µm, a rotational step of 0.70°, a rotational angle of 180° and a 3.1-s exposure time, using a 1-mm-thick aluminium filter. Images of each specimen were reconstructed from apex to the crown with dedicated software (NRecon v1.6.1.5) in approximately 450 slices. CTan v1.11 and CTVol v2.1 were used for three-dimensional visualization and qualitative analysis of the external and internal anatomy of the teeth. RESULTS: The tooth modification in all samples was classified as type E1 (one stone on the buccal surface of the crown) or E2 (two stones on the buccal surface of the crown). In the canine teeth, the cavities created to insert the inlay stone did not reach the pulp chamber. Conversely, in the maxillary incisors, the cavities clearly perforated the pulp chamber resulting in massive internal inflammatory resorption or partial calcification of the pulp cavity. In the premolar tooth, a small perforation of the pulp chamber under the buccal cusp, without morphological alteration of the intraradicular dentine, was observed. CONCLUSIONS: Microcomputed tomography analysis of teeth of the ancient Maya civilization showed that the inlay cavities cut reached the pulp chamber in the maxillary incisors and premolar teeth, with the potential to cause pulp and periapical disease.

Semiología de la pulpa: signos, síntomas y determinación del estado pulpar / Semiology of the pulp: signs, symptoms and pulp status determination

Es sabido que para toda intervención en medicina u odontología es imperativo proceder a realizar un correcto diagnóstico de la patología a tratgar; la operatoria dental no escapa a esta regla, debiendo el profesional realizar el diagnóstico de la lesión de los tejidos duros del diente pero además de su estado pulpar; y es precisamente aquí donde debe agudizar sus sentidos para observar la presencia de alguna patología y determinar en primera instancia el área de su incumbencia, o la derivación a la endodoncia. Es en este punto donde se cometen infinidad de errores ya que existe una sutil línea a partir de la cual la lesión pulpar pasa a un estadio irreversible. Es muy común intentar determinar el estado pulpar por la extensión de la lesión sin reparar en que existen grandes cavidades con tejido pulpar sano y pequeñas lesiones con patologías irreversibles. También es habitual que el profesional se guíe para la toma de decisiones por una radiografía, sin comprender que la misma no determina el estado pulpar. Por todo esto, es necesario conocer diferentes pruebas o tests que nos ayudan a diagnosticar con el menor margen de error posible, para encarar así un adecuado tratamiento.

Evidence-based review of clinical studies on pharmacology (non-anesthetic studies).

We have divided the analysis of pharmacology studies into studies on local anesthetics and studies on all other pharmacologic agents. This division reflects the large number of studies focusing on methods for obtaining effective anesthesia in patients and permits an independent focus on those clinical studies evaluating nonanesthetic drugs. In this section, we review that alternative class of agents, with an emphasis this year on clinical studies evaluating oral analgesics.