Outcome of Root Canal Treatment of Teeth with Asymptomatic Apical Periodontitis Treated with Foraminal Enlargement and 2% Chlorhexidine Gel: A Retrospective Cohort Study.

INTRODUCTION: This retrospective cohort study aimed to estimate the success rate (SR) of primary root canal treatment on teeth with a diagnosis of pulp necrosis (PN) and asymptomatic apical periodontitis (AAP) when using 2% chlorhexidine gel as an auxiliary chemical substance and foraminal enlargement instrumentation technique. METHODS: This study evaluated 178 patients with 206 teeth submitted to primary root canal treatment performed by graduate residents in endodontics. The inclusion criteria were patients who underwent treatment over a period of 1-7 years on teeth with a diagnosis of PN and AAP. The SR was evaluated clinically and radiographically and categorized considering strict (complete resolution of the periradicular lesion) or loose (reduction in the size of the existing periradicular lesion) criteria. Cases of clinical and/or radiographic absence of repair were classified as a failure. Two calibrated examiners independently assessed treatment outcomes using ImageJ software (National Institutes of Health, Bethesda, MD). RESULTS: The SRs were 81.1% (95% confidence interval, 75.7%-86.4%) and 87.4% (95% confidence interval, 82.8%-91.9%) when considering the strict or loose criteria, respectively. Females had a higher SR when strict criteria were applied. Also, the SR was significantly reduced when there was an increase in the patient's age. CONCLUSIONS: Teeth with a diagnosis of PN and AAP and treated with 2% chlorhexidine gel and foraminal enlargement achieved substantial SR. Sex and age were prognostic factors that played a significant role in the SR. Future randomized controlled trials should further investigate the effects of foraminal enlargement and 2% chlorhexidine gel as an auxiliary chemical substance.

Fluorosis. Antivet contra ácido clorhídrico / fluoride. Antivet vs hydrochloric acid

Introducción: La fluorosis dental es una hipomineralización del esmalte producida como respuesta a la ingesta de fluor por un periodo prolongado durante la formación del esmaltado. Es una alteración irreversible, que clínicamente se caracteriza por la presencia de delgadas líneas blanquecinas distribuidas en el esmalte dental correspondientes a la disposición de las periquimatías, y en grados más avanzados de la enfermedad se odservan cambios en toda la superficie del esmaltado que adquiere un aspecto opaco, como de piedra caliza. En los niveles más severos de flurosis dental, la presencia de hipomineralización, y el aumento en la porosidad del esmalte dental propicia la pérdida de porciones importantes de su estructura, produciendo fracturas, por lo que se deteriora la apariencia y funcionalidad de los dientes afectados. (1) La OMS recomienda que el valor de referencia para el fluoruro en el agua potable es de 1,5 mg /1.(2) El flúor es un gas halógeno, el más electronegativo de los elementos de la tabla periódica, con número atómico 19, prácticamente no existe libre en la naturaleza, sino asociado a otros elementos como: calcio y sodio. La principal vía de incorporación del flúor en el organismo humano es la digestiva. Es absorbido rápidamente en la mucosa del intestino delgado y del estómago, por un simple fenómeno de difusión. Una en los tejidos, depositándose preferentemente en los tejidos duros; se elimina por todas las vías de excreción, principalmente por orina. La cantidad de flúor en el organismo es variable y depende de la ingestión, inhalación, absorción y eliminación, así como de las características de los compuestos. Generalmente se concentra en huesos, cartílagos, dientes y placa bacteriana. El depósito de flúor varía con la edad y la excreción. En los niños, el 50% se fija en huesos y dientes en formación; en adultos, se deposita básicamente en huesos. (3) Existen diversos métodos para su eliminación. En esta investigación se realizaron 18 procedimientos a pacientes de ambos sexos. La metodología fue dividir en dos grupos de 8 personas cada uno, en el cual se utilizó Antivet en el primer grupo y ácido clorhídrico al 18% en el segundo grupo. Los casos fueron seleccionados al azar y posteriormente se observaron los cambios clínicos con cada grupo. En el primer grupo de personas que utilizaron Antivet, se mostró que en casos severos de fluorosis no era un método tan eficaz, ya que no elimina por completo las manchas marrones, sin embargo, es un procedimiento muy bueno para uso clínico cuando los grados de fluorosis son menores. En el segundo grupo de personas que utilizaron ácido clorhídrico al 18% se demostró la eficacia del tratamiento en fluorosis de grados avanzados, donde el esmalte está más del 50% dañado, por lo que es un excelente método de tratamiento con el debido control en su manipulación. Objetivo: Saber diferenciar los tipos de materiales y conocer los diferentes métodos para eliminación de flúor así como mostrar la diferencia entre tratamientos. Metodología: El tipo de estudio es explicativo y con el cual se espera contribuir al desarrollo del conocimiento científico. Su realización supone el ánimo de contribuir al desarrollo del saber científico. Consistió en seleccionar 16 pacientes, masculinos y femenonos y de distintas edades de entre 15 y 40 años. Se dividieron al azar, en 2 grupos de 8 personas cada uno para tratarlos con 2 productos diferentes. El primer grupo fue tratado con ácido clorhídrico al 18% y el segundo grupo con la marca comercial Antivet. Resultado y conclusión: La fluorosis dental es causada por ingestas excesivas de flúor. El uso del ácido clorhídrico es corrosivo, su aroma es penetrante y los cuidados con el paciente son mayores, ya que un mal uso al tener contacto con piel o mucosa creará necrosis. El Antivet tiene desventajas de costo y disponibilidad, pero su ventaja es que brinda más seguridad en su manipulación.

Introduction: Dental fluorosis is a hypomineralization of the enamel produced due to fluoride intake for a prolonged time during enamel formation. It is an irreversible alteration, which is clinically characterized by the presence of thin whitish lines distributed in the dental enamel corresponding to the disposition of the perikymata. In more advanced degrees of the disease, changes are observed in the entire enamel surface, which acquires an opaque appearance, like limestone. In the most severe levels of dental fluorosis, the presence of hypomineralization and increased porosity of the dental enamel leads to the loss of essential portions of its structure, producing fractures, thus deteriorating the appearance and functionality of the affected teeth. (1) The WHO recommends that the reference value for fluoride in drinking water is 1.5 mg/l. (2) Fluoride is a halogen gas, the most electronegative of the periodic table elements, with atomic number 19. It practically does not exist free in nature but is associated with other elements such as calcium and sodium. The primary way of incorporating fluorine into the human organism is through the digestive system. It is rapidly absorbed in the mucosa of the small intestine and stomach by a simple phenomenon of diffusion. Once absorbed, fluoride passes into the blood and is distributed in the tissues, preferentially deposited in hard tissues; it is eliminated by all excretion routes, mainly by the urine. The amount of fluoride in the body is variable and depends on ingestion, inhalation, absorption, elimination, and the characteristics of the compounds. It is generally concentrated in bones, cartilage, teeth, and bacterial plaque. Fluoride deposition varies with age and excretion. In children, 50% is fixed in bones and teeth information; it is basically deposited in bones in adults. (3) There are various methods for its elimination. In this research, 18 procedures were performed on patients of both sexes. The methodology was divided into two groups of 8 persons each, in which Antivet was used in the first group and 18% hydrochloric acid in the second group. The cases were randomly selected, and subsequently, the clinical changes were observed in each group. In the first group of people who used Antivet, it was shown that in severe cases of fluorosis, it was not such an effective method since it does not completely eliminate the brown stains. However, it is a very effective method for clinical use when the degrees of fluorosis are lower. In the second group of people who used 18% hydrochloric acid, the effectiveness of the treatment was demonstrated in advanced degrees of fluorosis, where the enamel is more than 50% damaged, making it an excellent method of treatment with due control in its manipulation. Objective: To differentiate the types of materials and to know the different methods for fluoride elimination as well as to show the difference between treatments. Methodology: The type of study is explanatory, and it is expected to contribute to the development of scientific knowledge. It was carried out to contribute to the development of scientific knowledge. It consisted of selecting 16 patients of both sexes and of different ages between 15 and 40 years old. They were randomly divided into two groups of 8 persons, each to be treated with two different products. The first group was treated with 18% hydrochloric acid, and the second group with the comercial brand Antivet. Result and conclusion: Dental fluorosis is caused by excessive fluoride intake. Hydrochloric acid is corrosive, its aroma is penetrating, and the care with the patient is greater since a wrong use when in contact with skin or mucosa will create necrosis. Antivet has disadvantages of cost and availability, but its advantage is that it provides more safety in its handling.

Effect of systemic antibiotic therapy on pulp repair following extrusive luxation and avulsion in a murine model: A histomorphological study.

BACKGROUND/AIM: The evidence for any benefit of systemic antibiotic therapy on pulp survival following extrusive luxation and avulsion is inconclusive. The aim of this study was to evaluate the effect of systemic antibiotic therapy with amoxycillin and tetracycline for 7 days on different aspects of dental pulp repair in a murine model. MATERIAL AND METHODS: The right maxillary incisor of 180 4 to 8-week-old male Wistar rats underwent extrusive luxation or avulsion. The animals were then treated with saline solution (control), tetracycline, or amoxicillin administered intra-gastrically for 7 days, and euthanized at 7, 15, and 30 days post-operatively. The layer of odontoblast cells, reparative dentin deposition, Hertwig's epithelial root sheath, pulp necrosis, and periapical inflammatory infiltrate were histomorphologically analyzed and scored. Mann-Whitney, Kruskal-Wallis, and Dunn tests were used to compare mean scores for the different procedures, treatments, and times (p ≤ .05). RESULTS: Significant differences were observed between luxated and avulsed teeth (p < .05). In luxated teeth, no differences were observed among treatments and times, except for more tertiary dentin deposition in the coronal third with the use of tetracycline compared with amoxicillin at 15 days (p < .05). In avulsed teeth, higher scores for the layer of odontoblast cells and lower scores for periapical inflammatory infiltrate at 7 days and pulp necrosis at 7 and 15 days were observed in the amoxicillin group compared to the saline and tetracycline groups (p < .05). At 30 days, however, no differences were observed among treatments. CONCLUSIONS: The use of systemic antibiotic therapy with tetracycline or amoxicillin for 7 days did not contribute to pulp repair following extrusive luxation or avulsion in rats. However, the results warrant further research into the use of amoxicillin for a more extended period of time in cases of avulsion.

Tratamiento del Diente Permanente Necrótico. Un Cambio de Paradigma en el Campo de la Endodoncia / Treatment of the Necrotic Permanent Tooth. A Paradigm Shift in Endodontics

RESUMEN: El tratamiento de dientes inmaduros necróticos es hoy un gran desafío clínico. La ausencia de cierre del ápice y el reducido grosor de las paredes de la dentina hacen que el tratamiento endodóntico del diente sea difícil e impredecible. Tradicionalmente, estos dientes han sido tratados con apexificación y obturación del canal radicular, sin embargo, con este tratamiento el diente permanece desvitalizado y con paredes de dentina frágiles y cortas, lo que compromete su pronóstico. La endodoncia regenerativa, por el contrario, busca revitalizar el diente e inducir una maduración de la raíz, y se basa en la utilización de las células madre mesenquimales presentes en la región periapical, los factores de crecimiento presentes en la dentina y un andamio que permite el crecimiento de tejido nuevo al interior del canal. Los resultados clínicos son alentadores, ya que en general existe maduración de la raíz y revascularización del diente, sin embargo, el tejido neoformado es tejido de tipo reparativo y, a excepción de estudios ocasionales, no se ha observado regeneración de dentina y pulpa. La endodoncia regenerativa se originó para tratar dientes inmaduros necróticos. Sin embargo, recientemente, estudios preliminares han expandido la aplicación de la endodoncia regenerativa a dientes maduros necróticos, es decir, en pacientes adultos. Los resultados clínicos son positivos y similares a los del diente inmaduro, si n embargo, la investigación referente a la revitalización de dientes maduros se encuentra en etapas tempranas y requiere de un mayor nivel de evidencia antes de ser ofrecida sistemáticamente como terapia a pacientes adultos. Los beneficios potenciales justifican mayor investigación al respecto. Este artículo resume la evidencia científica disponible con respecto a la revitalización de dientes inmaduros y maduros necróticos, sus fundamentos biológicos, los resultados esperados y limitaciones, así como el protocolo clínico.

ABSTRACT: Nowadays, the treatment of immature necrotic teeth is an important clinical challenge. The absence of apex closure and low thickness of the dentin walls, make endodontic treatment unpredictable and difficult. Traditionally, these teeth have been treated with apexification and obturation of the root canal. As a result of this treatment, the tooth remains devitalized and with fragile and short dentin walls, which compromises its prognosis. Regenerative endodontics, on the other hand, seeks to revitalize the tooth and induce root maturation, and is based on the use of mesenchymal stem cells present in the periapical tissues, growth factors present in the dentin and a scaffold that allows growth of new tissue in the root ca- nal. The clinical results are encouraging, since generally, there is root maturation and revascularization of the tooth. However, the newly formed tissue is reparative tissue and with the exception of some studies, no regeneration of dentin and pulp has been reported. Regenerative endodontics emerged to treat necrotic immature teeth. However, recently, preliminary studies have applied regenerative endodontics in mature necrotic teeth, in adult patients. Preliminary results are positive and are similar to those of immature teeth. Nevertheless, research regarding the revitalization of mature teeth is in the early stages and requires further evidence before being systematically administered as therapy in adult patients. However, the potential benefits justify further research in this regard. This article summarizes the available scientific evidence regarding the revitalization of immature and mature necrotic teeth, their biological basis, the expected results and limitations, as well as the clinical protocols for each case.

Treatment outcomes of pulp revascularization in traumatized immature teeth using calcium hydroxide and 2% chlorhexidine gel as intracanal medication.

OBJECTIVE: Pulp revascularization is an effective treatment for immature necrotic teeth. Calcium hydroxide has been used in pulp revascularization as an intracanal medication due to its antimicrobial action and the non-exhibition of crown discoloration and cytotoxicity for stem cells from the apical papilla. Our study aimed to investigate the clinical success and quantitative radiographic changes of root development in immature traumatized teeth using calcium hydroxide plus 2% chlorhexidine gel as intracanal medication. METHODOLOGY: In this retrospective study, 16 patients were treated with a standardized pulp revascularization protocol. Calcium hydroxide and 2% chlorhexidine gel were manipulated in a 1:1 (v/v) ratio and inserted into root canals with Lentulo spirals (Dentsply Maillefer, Baillaigues, Switzerland). Patients were followed up for a period from 9 to 36 months for the evaluation of clinical and radiological data. Radiographic measurements of root length, root width, apical diameter, and MTA placement from the apex were quantified using software ImageJ. Wilcoxon test and t-test were used, according to nonparametric or parametric data, respectively, for changes over time in root length, root width, and apical diameter. RESULTS: Fifteen teeth survived during the follow-up period (93.75%) and met the criteria for clinical success. Although the changes seem to be very small in many cases, significant increases in the average root length (14.28%, p<0.0001), root width (8.12%, p=0.0196), and decrease in apical diameter (48.37%, p=0.0007) were observed. MTA placement from the apex and age at the time of treatment was not significantly associated with the quantitative radiographic outcomes. CONCLUSIONS: Pulp revascularization in traumatized immature teeth treated with calcium hydroxide plus 2% chlorhexidine gel as intracanal medication had high success and survival rates, showing periodontal healing and resolution of signs and symptoms. However, concerning the continued root development, the outcomes can still be considered unpredictable.

Treatment outcomes of pulp revascularization in traumatized immature teeth using calcium hydroxide and 2% chlorhexidine gel as intracanal medication

Abstract Objective Pulp revascularization is an effective treatment for immature necrotic teeth. Calcium hydroxide has been used in pulp revascularization as an intracanal medication due to its antimicrobial action and the non-exhibition of crown discoloration and cytotoxicity for stem cells from the apical papilla. Our study aimed to investigate the clinical success and quantitative radiographic changes of root development in immature traumatized teeth using calcium hydroxide plus 2% chlorhexidine gel as intracanal medication. Methodology In this retrospective study, 16 patients were treated with a standardized pulp revascularization protocol. Calcium hydroxide and 2% chlorhexidine gel were manipulated in a 1:1 (v/v) ratio and inserted into root canals with Lentulo spirals (Dentsply Maillefer, Baillaigues, Switzerland). Patients were followed up for a period from 9 to 36 months for the evaluation of clinical and radiological data. Radiographic measurements of root length, root width, apical diameter, and MTA placement from the apex were quantified using software ImageJ. Wilcoxon test and t-test were used, according to nonparametric or parametric data, respectively, for changes over time in root length, root width, and apical diameter. Results Fifteen teeth survived during the follow-up period (93.75%) and met the criteria for clinical success. Although the changes seem to be very small in many cases, significant increases in the average root length (14.28%, p<0.0001), root width (8.12%, p=0.0196), and decrease in apical diameter (48.37%, p=0.0007) were observed. MTA placement from the apex and age at the time of treatment was not significantly associated with the quantitative radiographic outcomes. Conclusions Pulp revascularization in traumatized immature teeth treated with calcium hydroxide plus 2% chlorhexidine gel as intracanal medication had high success and survival rates, showing periodontal healing and resolution of signs and symptoms. However, concerning the continued root development, the outcomes can still be considered unpredictable.

Cellular profile of primary molars with pulp necrosis after treatment with antibiotic paste.

The interradicular region of primary molars is permeated by many foramina, channels and accessories that connect the pulp cavity with the periapical tissues anatomically. Thus, pulp decomposition products or drugs used in endodontic treatment can trigger inflammatory reactions. The aim of this study was to evaluate the blood cell profile of the alveolar region after extraction of primary molars treated with CTZ paste. Forty-eight primary molars were selected with clinical and radiographic signs of extraction. The sample was divided into three groups with 16 teeth each: Group 1-healthy teeth; Group 2-untreated decayed teeth; and Group 3-teeth treated with CTZ paste. Immediately after the extraction, blood from the interface of the tooth socket was collected and smears were performed for further evaluation. The slides were stained by the Fast Panoptic® method and analysed by two previously trained examiners who counted the leucocytes in sets of 100 cells/slide, differentiating them into neutrophils, lymphocytes, monocytes, eosinophils and basophils. The data were analysed statistically by the MANOVA test. The blood samples from Group 2 differed significantly from Group 1 samples for all classes of leucocytes, except basophils, with higher average for lymphocytes (62.56), monocytes (7.81) and eosinophils (2.31). For Group 3, there was a relative difference (P < 0.05) to Group 2, of monocytes and eosinophils values. The blood cellularity interface in the tooth socket of primary teeth treated with CTZ paste is similar to those of healthy, exfoliated teeth and physiologically different from untreated decayed teeth.

Tissue characterization following revascularization of immature dog teeth using different disinfection pastes.

Revascularization of immature teeth with necrotic pulps traditionally involves the use of triple antibiotic paste, which may sometimes lead to undesirable complications. The objective of this study was to assess tissue repair in immature dog teeth with apical periodontitis subjected to revascularization, comparing two different pastes used for root canal disinfection. Apical periodontitis was induced in 30 dog premolars. Teeth were randomly divided into three experimental groups: root canals filled with triple antibiotic paste (n = 10); root canals filled with 1% propolis paste (n = 10); and no medication (n = 10). An additional group (n = 10, no intervention) was used as control. After 7 months, the jaws were histologically evaluated for the following variables: newly formed mineralized tissue (present/absent); vital tissue in the canal space (absent/periodontal ligament-like/pulp-like); apical extension of root (present/absent); and severity of inflammatory process (absent/mild/moderate/severe). There were no statistically significant differences among the experimental groups in new mineralized tissue formation and apical root development. The formation of vital tissue in the canal space, in turn, was statistically different between the triple paste and propolis groups: vital tissues were present in all revascularized teeth disinfected with propolis paste (100%), compared to 71% of those disinfected with the triple paste. Severity of inflammatory process was different between the triple paste and no medication groups. The new tissues formed onto canal walls and in the root canal space showed characteristics of cementum and periodontal ligament, respectively. Propolis may have some advantages over the triple paste for the revascularization of immature teeth.

Tratamiento con pasta 3 Mix-MP en molares primarios no vitales: estudio preliminar / Treatment of nonvital primary molars with 2 Mix-MP paste: a preliminary study

Estimar la frecuencia de éxito clínico-radiográfico del tratamiento endodóntico no instrumentado con pasta 3Mix-MP en molares primarios con diagnóstico de necrosis pulpar. Materiales y métodos: estudio experimental, prospectivo y longitudinal, realizado en la Cátedra de Odontología Integral Niños de la FOUBA (agosto 2014 - agosto 2015). Formaron parte de la investigación 44 molares primarios con diagnóstico de necrosis pulpar, de 36 niños (6,07 +/- 1,63 años), sin compromiso inmunológico ni metabólico y que junto con sus responsables legales brindaron el consentimiento informado. Se realizó el tratamiento endodóntico no instrumentado con pasta 3Mix-MP (metronidazol, minociclina, ciprofloxacina 1:1:1 y vehículos macrogol, propilenglicol 1:1) y restauración definitiva con corona de acero. Los molares fueron evaluados por dos examinadores al mes, 3, 6 y 12 meses. Se calcularon porcentajes con sus intervalos de confianza del 95 por ciento. Resultados: al mes, la tasa de éxito clínico fue de 97.72 por ciento (87.96-99.97) y la de éxito radiográfico de 93.18 por ciento (81.31-98.61). Fue posible el seguimiento del 65.85 por ciento de la muestra a los 3 meses, del 34.14 por ciento a los 6 meses y del 24.39 por ciento a los 12 meses, revelando un 100 por ciento de éxito clínico-radiográfico en los tratamientos evaluados. Conclusión: en los casos y períodos estudiados, esta terapéutica mostró un buen comportamiento clínico y radiográfico. Son necesarios estudios con mayor tamaño muestral y mayor período de seguimiento para proponerla como alternativa de tratamento...

Tissue characterization following revascularization of immature dog teeth using different disinfection pastes

Abstract Revascularization of immature teeth with necrotic pulps traditionally involves the use of triple antibiotic paste, which may sometimes lead to undesirable complications. The objective of this study was to assess tissue repair in immature dog teeth with apical periodontitis subjected to revascularization, comparing two different pastes used for root canal disinfection. Apical periodontitis was induced in 30 dog premolars. Teeth were randomly divided into three experimental groups: root canals filled with triple antibiotic paste (n = 10); root canals filled with 1% propolis paste (n = 10); and no medication (n = 10). An additional group (n = 10, no intervention) was used as control. After 7 months, the jaws were histologically evaluated for the following variables: newly formed mineralized tissue (present/absent); vital tissue in the canal space (absent/periodontal ligament-like/pulp-like); apical extension of root (present/absent); and severity of inflammatory process (absent/mild/moderate/severe). There were no statistically significant differences among the experimental groups in new mineralized tissue formation and apical root development. The formation of vital tissue in the canal space, in turn, was statistically different between the triple paste and propolis groups: vital tissues were present in all revascularized teeth disinfected with propolis paste (100%), compared to 71% of those disinfected with the triple paste. Severity of inflammatory process was different between the triple paste and no medication groups. The new tissues formed onto canal walls and in the root canal space showed characteristics of cementum and periodontal ligament, respectively. Propolis may have some advantages over the triple paste for the revascularization of immature teeth.

Intracanal delivery of Resolvin E1 controls inflammation in necrotic immature rat teeth.

INTRODUCTION: Pulp necrosis in immature teeth and the resulting periodontal apical inflammation negatively affect root formation. Resolvin E1 (RvE1) is a lipid-derived endogenous pro-resolution molecule that controls inflammation. The aim of this investigation was to evaluate the impact of RvE1 applied as an intracanal medication on root formation in nonvital immature teeth. METHODS: To arrest root development, pulpectomy was performed in the lower first molars of 4-week-old Wistar rats. After 3 weeks, irrigation with 2.5% sodium hypochlorite and 0.9% sterile saline was performed, and either a triple antibiotic paste (TAP) or RvE1 in saline was applied into the root canals. In the control group, access openings drilled into molars were left exposed to the oral environment. Root development and periapical repair were evaluated radiographically and histologically at 3 and 6 weeks after treatment. RESULTS: RvE1 reduced periapical lesion size compared with the control at 3 weeks, which was similar to TAP. Inflammatory response in the RvE1-treated group was markedly reduced compared with both TAP and control specimens. At 6 weeks, root development was observed in both groups, but RvE1 treatment produced less cellularity with more regular calcified tissue deposition. CONCLUSIONS: RvE1 and TAP had a positive impact on reducing inflammation and promoting root formation. RvE1 was more effective in reducing inflammation at earlier stages. RvE1 has potential to be used as root canal dressing to control inflammation in endodontically compromised teeth before complete root formation. Stability of RvE1 within the root canal and its delivery are issues to be addressed before its clinical use.

Effects of calcium hydroxide on cytokine expression in endodontic infections.

INTRODUCTION: The use of calcium hydroxide is an effective step in killing bacteria that remain after cleaning and shaping procedures. It also induces hard-tissue formation and is effective for stopping inflammatory exudates. METHODS: The aim of this study was to assay and to compare the influence of calcium hydroxide on periapical interstitial fluid from human root canals. The mRNA expression levels of the cytokines interferon (IFN)-γ, tumor necrosis factor-α, interleukin (IL)-1ß, IL-17A, and IL-10 as well as the chemokine MCP-1 were assayed by real-time polymerase chain reaction immediately after root canal cleaning and 15 days later. RESULTS: Levels of IL-1ß, IFN-γ, IL-10, and the chemokine CCL2/MCP-1 were increased in teeth without endodontic dressings. With calcium hydroxide interappointment dressings, no statistically significant changes were observed in cytokine mRNA expression. However, when comparing teeth that received the medication with those that did not, expression levels of IL-1ß, IFN-γ, and IL-10 were statistically lower in those teeth that received calcium hydroxide. CONCLUSIONS: Analyses of cytokines and the chemokine CCL-2/MCP-1 demonstrated the benefits of calcium hydroxide as a root canal dressing because it impedes the increase of all mediators during the experimental time.

Response to intracanal medication in immature teeth with pulp necrosis: an experimental model in rat molars.

INTRODUCTION: The present study aimed at developing an experimental model in rat molars for evaluating treatment strategies in necrotic immature teeth. METHODS: To define the periods to be adopted in the experimental procedures and to confirm induction of periapical lesions and interruption of root embryogenesis, the left lower first molars of 4-weeks-old Wistar rats underwent pulpectomy and were left open to the oral environment. Comparisons with the right lower first molars (vital teeth) were performed in animals with ages of 7, 10, 13, and 16 weeks. In another group of animals the teeth were left open for 3 weeks, and then interventions for disinfection including the use of an antibiotic paste were carried out. Root formation was then assessed after 3 and 6 weeks on the basis of radiographic and histologic evaluation. RESULTS: Vital teeth showed increase of root length and hard tissue thickness throughout the experimental periods. On the other hand, induction of necrosis arrested root formation. Teeth subjected to disinfection with sodium hypochlorite associated with the triple antibiotic paste showed significant reduction of periapical lesions, gain in root length, and increased wall thickness compared with the control (P < .05). CONCLUSIONS: The root canal disinfection protocol used was able to reduce periapical lesion size and improve root development. The experimental model presented should contribute to studies that aim at improving therapeutic strategies for necrotic immature teeth by using a rat model.

Photodynamic therapy in endodontic treatment of deciduous teeth.

The purpose of this study was to evaluate photodynamic therapy in deciduous teeth with necrotic pulp by means of fully quantifying viable bacteria, before and after instrumentation and after the use of photodynamic therapy. Radicular canal cultures were conducted (n = 10): the first one was performed right after access and location of the radicular canal; the second was performed after the conclusion of chemical-mechanical instrumentation, and the last one after photodynamic therapy. The photodynamic therapy was performed with 4 J/cm energy low-intensity diode together with toluidine blue. The results (log(10)) were submitted to a descriptive analysis and Wilcoxon test. The percentage of reduction was submitted to the Mann-Whitney test. The instrumentation resulted in a reduction of 82.59% of viable bacteria, and, after photodynamic therapy, the microbial reduction observed was 98.37% (P = 0.0126). Photodynamic therapy is recommended as adjunct therapy for microbial reduction in deciduous teeth with necrotic pulp.

Antimicrobial effects of photodynamic therapy on patients with necrotic pulps and periapical lesion.

This study analyzed the antimicrobial effect of photodynamic therapy (PDT) in association with endodontic treatment. Twenty patients were selected. Microbiological samples were taken after accessing the canal, endodontic therapy, and PDT. At the end of the first session, the root canal was filled with Ca(OH)(2), and after 1 week, a second session of the therapies was performed. Endodontic therapy gave a mean reduction of 1.08 log. The combination with PDT significantly enhanced the reduction (1.83 log, p = 0.00002). The second endodontic session gave a similar diminution to the first (1.14 log), and the second PDT was significantly more effective than the first (p = 0.002). The second total reduction was significantly higher than the second endodontic therapy (p = 0.0000005). The total first + second reduction (3.19 log) was significantly different from the first combination (p = 0.00006). Results suggest that the use of PDT added to endodontic treatment leads to an enhanced decrease of bacterial load and may be an appropriate approach for the treatment of oral infections.

Efecto antibacteriano del hidróxido de calcio en los conductos radiculares con pulpa infectada / Antibacterial effect of calcium hydroxide in root canals with infected pulp

En los casos de gangrena pulpar se han utilizado varios medicamentos de gran efecto antibacteriano pero que resultan muy irritantes. El hidróxido de calcio usado como recubrimiento pulpar en caries dentinaria profunda propicia la formación de un puente dentinario y tiene efecto antimicrobiano, antiinflamatorio y como sellador. El objetivo del trabajo fue valorar el efecto antibacteriano del hidróxido de calcio en el tratamiento de conductos radiculares con pulpa infectada. Se estudiaron 36 piezas dentarias con el diagnóstico de gangrena pulpar, realizando cultivos para la detección de bacterias aerobias y anaerobias antes y después del tratamiento. Se observó un aumento significativo en el número de dientes negativos al cultivo después del tratamiento, tanto para microorganismos aerobios (p<0.000001) como para anaerobios (p<0.000001), así como también una disminución significativa en el número de colonias bacterianas tanto de aerobios (p=0.010) como de anaerobios (p=0.0016). Fue notoria la ausencia de dolor después de la aplicación del medicamento

A comparison of erythromycin and cefadroxil in the prevention of flare-ups from asymptomatic teeth with pulpal necrosis and associated periapical pathosis.

In a previous study by our group with patients having asymptomatic teeth with pulpal necrosis and an associated periapical radiolucent lesion (PN/PL), it was shown that prophylactic administration of penicillin V or erythromycin (high-dose, 1-day regimen) resulted in a low incidence of flare-up (mean = 2.2%) and a low incidence of swelling and pain not associated with flare-up. No hypersensitivity responses occurred, and gastrointestinal side effects were found primarily with the erythromycins. To ascertain whether a single-dose administration of a long-acting 1-gm tablet of the cephalosporin antibiotic cefadroxil would result in a similar outcome, the present study was undertaken with 200 patients having quiescent PN/PL. The patients were randomly given either cefadroxil or erythromycin (base or stearate). Evaluations of flare-up were done 1 day, 1 week, and 2 months after endodontic treatment. A 2.0% flare-up incidence was found, with no statistically significant differences for cefadroxil (1.0%), stearate (2.0%), or base (4.0%). No hypersensitivity responses occurred. Gastrointestinal side effects were found primarily with the erythromycins (19.0%). The results showed that a 1-gm, single-dose regimen of cefadroxil was as effective as erythromycin and penicillin in preventing flare-ups and serious sequelae. A comparative analysis of the data from our first study (no peritreatment antibiotics) and the pooled data from our last three investigations (including the current trial) showed that peritreatment antibiotic coverage significantly reduced flare-ups and serious sequelae after endodontic treatment of asymptomatic PN/PL (p less than 0.001).