Expert consensus on difficulty assessment of endodontic therapy.

Endodontic diseases are a kind of chronic infectious oral disease. Common endodontic treatment concepts are based on the removal of inflamed or necrotic pulp tissue and the replacement by gutta-percha. However, it is very essential for endodontic treatment to debride the root canal system and prevent the root canal system from bacterial reinfection after root canal therapy (RCT). Recent research, encompassing bacterial etiology and advanced imaging techniques, contributes to our understanding of the root canal system's anatomy intricacies and the technique sensitivity of RCT. Success in RCT hinges on factors like patients, infection severity, root canal anatomy, and treatment techniques. Therefore, improving disease management is a key issue to combat endodontic diseases and cure periapical lesions. The clinical difficulty assessment system of RCT is established based on patient conditions, tooth conditions, root canal configuration, and root canal needing retreatment, and emphasizes pre-treatment risk assessment for optimal outcomes. The findings suggest that the presence of risk factors may correlate with the challenge of achieving the high standard required for RCT. These insights contribute not only to improve education but also aid practitioners in treatment planning and referral decision-making within the field of endodontics.

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.

Regenerative endodontic therapy in mature teeth with necrotic pulp and apical periodontitis using two disinfection protocols.

OBJECTIVE: This study compared the effect of diode laser (DL) 980 nm and double antibiotic paste (DAP) on response of mature teeth with necrotic pulp and apical periodontitis to regenerative endodontic therapy in a dog model. METHODS: Pulp necrosis and periapical pathosis were induced in 40 mature double rooted premolars in four 2-year-old mongrel dogs. These teeth were randomly divided according to disinfection protocol into four equal groups (10 teeth each/20 roots), group I: DAP; group II: DL980 nm; group III: positive control (without treatment) and group IV: negative control (untouched teeth). These groups were further subdivided into 2 subgroups (5 teeth each/10 roots) according to evaluation period, subgroup (A): one month and subgroup (B): three months. Revascularization techniques were performed using bleeding induction and application of platelet rich fibrin (PRF). The coronal cavities were sealed with mineral trioxide aggregate (MTA) and glass ionomer cement. The inflammatory response, vital tissue in-growth, new hard tissue formation and bone resorption were assessed. Statistical analysis was done utilizing ANOVA, Tukey's post hoc and paired t tests. RESULTS: In both subgroups, there were no significant differences between DAP and DL980 in terms of inflammatory cell count, vital tissue in-growth, new hard tissue formation and bone resorption (P ≤ 0.05). CONCLUSION: Diode laser 980 nm can alternate DAP as a disinfection method of the root canal during RET for mature necrotic teeth, therefore it may accelerate regenerative endodontic therapy for both the patient and dentist and allows for RET in a single appointment.

Effectiveness of endodontic tissue engineering in treatment of apical periodontitis: A systematic review.

BACKGROUND: Regenerative endodontics has evolved in recent years with tissue engineering concepts in particular appearing promising. Endodontic tissue engineering (ETE) describes the various approaches based on the orthograde introduction of scaffolds or biomaterials (with or without cells) into the root canal to achieve pulp tissue regeneration. There are currently no systematic reviews investigating whether ETE is a suitable method for the treatment of endodontic disease in both mature and immature permanent teeth. OBJECTIVES: The purpose of this systematic review was to determine the effectiveness of ETE in permanent teeth with pulp necrosis in comparison with conventional endodontic treatment. METHODS: We searched MEDLINE, Embase and the Cochrane Library for published reports as well as Google Scholar for grey literature up to November 2021. Included were studies of patients with permanent immature or mature teeth and pulp necrosis with or without signs of apical periodontitis (P) comparing ETE (I) with calcium hydroxide apexification, apical plug and root canal treatment (C) in terms of tooth survival, pain, tenderness, swelling, need for medication (analgesics and antibiotics), radiographic evidence of reduction in apical lesion size, radiographic evidence of normal periodontal ligament space, function (fracture and restoration longevity), the need for further intervention, adverse effects (including exacerbation, restoration integrity, allergy and discolouration), oral health-related quality of life (OHRQoL), presence of sinus tract and response to sensibility testing (O). An observation period of at least 12 months was mandatory (T) and the number of patients in human experimental studies or longitudinal observational studies had to be at least 20 (10 in each arm) at the end (S). Risk of bias was appraised using the Cochrane risk-of-bias (RoB 2) tool. Two authors independently screened the records, assessed full texts for eligibility and evaluated risk of bias. Heterogeneity of outcomes and limited body of evidence did not allow for meta-analysis. RESULTS: Two randomized clinical trials investigating cell transplantation approaches with a total of 76 participants (40 treated immature teeth and 36 treated mature teeth) were included for qualitative analysis. Both studies had moderate concerns in terms of risk of bias. Due to the lack of homogeneity a meta-analysis was not possible. Tooth survival for ETE, root canal treatment and apexification was 100% after 12 months. Teeth treated with ETE showed a higher number of cases with positive pulpal responses to sensitivity tests and with blood perfusion compared with root canal treatment or apexification. DISCUSSION: This systematic review highlights that there is limited evidence for ETE approaches. Even though the results of this review suggest a high survival with ETE in mature and immature teeth, there is a moderate risk of bias due to methodological limitations in the included studies, so the overall results should be interpreted with caution. Lack of a robust control group was a common problem during literature screening, and outcomes besides dental survival were reported inconsistently. Future clinical trials need to address methodical as well as assessment concerns and report long-term results. CONCLUSION: The benefits and high survival rates reported for ETE techniques suggest that this procedure might be an alternative to conventional procedures for permanent teeth with pulpal necrosis. However, more appropriate studies are needed to derive clinical recommendations. REGISTRATION: PROSPERO (CRD42021266350).

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.

Deciduous Tooth Pulp Autotransplantation for the Regenerative Endodontic Treatment of Permanent Teeth With Pulp Necrosis: A Case Series.

INTRODUCTION: In young individuals, deciduous tooth pulp might be used as a natural, biologic scaffold for the regenerative endodontic treatment (RET) of young permanent teeth with necrotic pulps and apical periodontitis. The present case series demonstrates the clinical and radiographic outcomes of a novel RET using deciduous pulp autotransplantation in traumatized, necrotic young permanent incisors. METHODS: Five previously traumatized maxillary incisors of four 8- to 11.5-year-old patients were treated with a RET protocol that used 2.5% NaOCl irrigation and placement of calcium hydroxide dressing in the first visit. After 4 weeks, the intracanal medication was removed, and the whole pulp tissue harvested from the neighboring maxillary deciduous canine was transplanted into the disinfected root canal without induced apical bleeding. Following placement of a mineral trioxide aggregate coronal barrier, the access cavities were restored with acid-etch resin composite. The root canals of donor primary canines were filled with calcium hydroxide-iodoform paste and were restored as with the permanent incisors. RESULTS: Three patients were followed-up for 24 months, and 1 patient for 12 months. All teeth demonstrated radiographic evidence of complete periapical healing, slight increase in dentinal wall thickness, and continued apical closure in the absence of clinical symptoms. A positive response to cold test was obtained in 1 incisor at 12 months and 2 at 24 months. CONCLUSIONS: Based on 12- and 24-month clinical and radiographic findings, the present cases demonstrate a favorable outcome of a RET protocol using deciduous pulp autotransplantation in young permanent incisors with pulp necrosis.

Evaluation of Ozone Therapy in Endodontic Treatment of Teeth with Necrotic Pulp and Apical Periodontitis: A Randomized Clinical Trial.

INTRODUCTION: The aim of this study was to compare the effect of different application techniques of ozone on the prevalence of postendodontic pain in patients undergoing single-visit root canal treatment. METHODS: hundred eight patients with necrotic pulp in single-rooted teeth and apical periodontitis participated in the trial. A standard single-visit endodontics protocol was followed with 5.25% sodium hypochlorite and rotary nickel-titanium files. After shaping and cleaning, patients were randomly allocated into the following groups: group 1 (n = 21), ozone treatment with no activation (NA); group 2 (n = 22), ozone treatment with manual dynamic activation (MDA); group 3, (n = 21), ozone treatment with passive ultrasonic activation (PUA); group 4 (n = 23), ozone treatment with sonic activation (SA); and group 5 (n = 21), no ozone treatment (the control group). Patient levels of discomfort were recorded at 6 different time intervals using the visual analog scale (VAS). Comparison of the mean difference between the groups and time intervals was performed using 2-way analysis of variance followed by a post hoc Bonferroni test. The level of significance was set at 5%. RESULTS: VAS scores were highest for the control > NA > MDA > SA > PUA groups. A statistically significant reduction in VAS scores was observed in the PUA and SA groups in comparison with the NA, control, and MDA groups. Timewise comparison showed a highly significant decline in VAS scores at all time intervals (P < .001). CONCLUSIONS: Ultrasonic and sonic activation of ozone resulted in less pain in patients undergoing single-visit endodontics compared with no ozone treatment.

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.

Contemporary Microbial and Antimicrobial Considerations in Regenerative Endodontic Therapy.

INTRODUCTION: Regenerative endodontic therapy (RET) has gained considerable attention and wide approval. Although it is being performed routinely, the outcomes remain unpredictable, and the optimal approaches for treatment are not established. It has been shown that bacterial persistence in root canals in these cases significantly interferes with healing and root maturation. However, few objective clinical studies have evaluated the complex microflora present in the infections or the efficacy of various clinical procedures. In addition, the extent of the infection and biofilm maturation in immature teeth with necrotic pulp has been understudied. Furthermore, most models used in preclinical evaluation of these issues do not fully elucidate the complexity or variability of the clinical situation. RESULTS AND CONCLUSION: In this review, the main biological and clinical problems pertaining to RET will be discussed. Contemporary analysis of complex microbial communities will be reviewed with emphasis on how these types of analyses can provide clinically useful data. In addition, current and proposed approaches for the effective disinfection of the root canal environment without interference with stem cell viability or integrity of the dentin matrix in these cases will be explored. The future of research in this field, including better and more customizable approaches in RET, in light of recent technological advances and progress in endodontics, will be outlined.

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.

Evaluation of antibacterial activity of propolis on regenerative potential of necrotic immature permanent teeth in dogs.

BACKGROUND: This study evaluated the antibacterial efficiency and ability of propolis to promote regeneration of immature permanent non-vital dogs' teeth. METHODS: Ninety six immature permanent premolars teeth in 6 mongrel dogs were divided randomly into: experimental teeth (N = 72) and control teeth (N = 24). Periapical pathosis was induced in all experimental and positive control teeth. Experimental teeth were classified according to the used intra-canal medication into: group I (N = 36), propolis paste was used and group II (N = 36), triple antibiotic paste (TAP) was used. Bacteriologic samplings were collected before and after exposure to intra-canal medicaments. After the disinfection period (3 weeks), revascularization was induced in all experimental teeth. Each group was subdivided according to the root canal orifice plug into: subgroup A (N = 18), propolis paste was used and subgroup B (N = 18), mineral trioxide aggregates (MTA) was used. Each subgroup was further subdivided according to the evaluation period into 3 subdivisions (6 teeth each): subdivision 1; after 2 weeks, subdivision 2; after one month and subdivision 3; after 2 months. Positive control group had 12 teeth with induced untreated periapical pathosis. Negative control group had 12 untouched sound teeth. All teeth were evaluated with radiography and histology. The bacteriologic and radiographic data were analyzed using repeated measures ANOVA and post-hoc Tukey tests. The histologic data were analyzed using Kruskal-Wallis test, Mann-Whitney U test with Bonferroni's adjustment and Chi-square test. The significance level was set at P ≤ .05. RESULTS: There was no significant difference in the antibacterial effectiveness between TAP and propolis groups (P > .05). In all subdivisions, there was no significant difference between the experimental groups in terms of increase in root length and dentin thickness, decrease in apical closure, new hard tissue formation, vital tissue formation inside the pulp canal and apical closure scores (P > .05). CONCLUSION: Propolis can be comparable with TAP as a disinfection treatment option in regenerative endodontic. As a root canal orifice plug after revascularization of necrotic immature permanent teeth in dogs, propolis induces a progressive increase in root length and dentin thickness and a decrease in apical diameter similar to those of MTA.

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.

Efficacy of various intracanal medicaments against aerobic and facultative anaerobic microorganism found in human primary teeth with necrotic pulp: A randomized clinical trial.

AIM: The aim of this in vivo study is to evaluate the antimicrobial efficacy of calcium hydroxide (Ca(OH)2), chlorhexidine (CHX), and metronidazole gel as intracanal medicaments against aerobic and facultative anaerobic microorganisms found in root canals of human primary teeth with necrotic pulp. SETTING AND DESIGN: It is a double-blinded randomized clinical trial. MATERIALS AND METHODS: Pulp canals of 45 single-rooted primary maxillary anterior teeth with pulp necrosis in 34 children were included in the study. They were divided into three groups of 15 samples each: Group I: Ca(OH)2; Group II: 1% CHX gel; and Group III: 1% metronidazole gel. Microbial count was obtained from each tooth at two different stages - (1) after instrumentation and (2) after placement of the medication. Statistical analysis using the SPSS 10.0 software program (SPSS Inc., Chicago, IL, USA) with Wilcoxon signed-rank test after grouping the samples was performed. RESULTS: Ca(OH)2, 1% CHX gel, and 1% metronidazole gel were ineffective in completely eliminating aerobic and facultative anaerobic microorganism from root canal of human primary teeth with necrotic pulp. CONCLUSION: None of the commonly used intracanal medicaments, that is Ca(OH)2, 1% CHX gel, and 1% metronidazole gel, was effective in completely eliminating aerobic and facultative anaerobic microorganism from root canal of human primary teeth with necrotic pulp. Ineffectiveness of these medicaments against aerobic and facultative anaerobic microorganism has opened new door of research regarding the manner of bacterial growth in unfavorable environmental and nutritional conditions, the way root canal environment favors biofilm formation and the use of suitable intracanal medicaments against single and multispecies biofilms.

Dental students' knowledge regarding the indications for antibiotics in the management of endodontic infections.

AIM: To determine the knowledge of undergraduate Spanish dental students regarding the indications of systemic antibiotics in the management of endodontic infections. METHODOLOGY: The final year dental students from four Spanish dental schools were requested to answer a one-page questionnaire on the indications for systemic antibiotics in the treatment of endodontic infections. One hundred and seventy-five students were asked to participate in this research. Data were analysed using descriptive statistics and chi-square test. RESULTS: One hundred and four students (93.7%) completed satisfactorily the survey and were included in the study. The average duration of antibiotic therapy was 7.0 ± 2.0 days. All respondents chose amoxicillin as the first-choice antibiotic in patients with no medical allergies, alone (47%) or associated with clavulanic acid (53%). The first drug of choice for patients with an allergy to penicillin was clindamycin 300 mg (99%). For cases of irreversible pulpitis, up to 63% of students would prescribe antibiotics. For the scenario of a necrotic pulp, symptomatic apical periodontitis and no swelling, 44% would prescribe antibiotics. Almost 40% of students would prescribe antibiotics for necrotic pulps with asymptomatic apical periodontitis and a sinus tract. CONCLUSIONS: It is necessary for the Spanish schools of dentistry to improve students' knowledge about antibiotics and their indications in endodontics. Interactive education analysing real endodontic cases using problem-based learning would help students acquire better skills in prescribing antibiotics in pulp-periapical pathosis.

Clinical and Radiographic Assessment of the Efficacy of a Collagen Membrane in Regenerative Endodontics: A Randomized, Controlled Clinical Trial.

INTRODUCTION: Recent reviews confirm a general lack of randomized, controlled clinical studies on the efficacy of regenerative endodontics in immature teeth affected by pulp and periapical diseases. Moreover, we have no evidence of the curative efficacy of collagen membranes used as scaffolds in regenerative endodontics. Here, we evaluated whether a Bio-Gide collagen membrane (Geistlich Pharma AG, Wolhusen, Switzerland) has efficacy in promoting dentin formation in regenerative endodontics. METHODS: Forty-three patients yielding a total of 46 nonvital immature teeth were divided randomly into 2 groups. Subsequent to chemomechanical preparation, regenerative endodontics with (the experimental group) and without (the control group) Bio-Gide were performed. All cases were followed up clinically and radiographically every 3 months for at least 6 months. Quantitative analyses using an imaging program yielded percentage changes in root dimensions based on a comparison between preoperative and recall radiographs. RESULTS: The results of 40 patients (43 teeth) were included in the final analyses. All patients from both groups showed clinical success with complete resolution of signs and symptoms. Radiographically, the thickness of the dentin wall at the middle third of the root was higher for the experimental group than the control group. However, other indicators were comparable between both groups. CONCLUSIONS: The use of the Bio-Gide collagen membrane promoted the development of the dentin wall in the middle third of the root in patients undergoing regenerative endodontic procedures. The convenience of operation and the assured positioning of the sealing material make the Bio-Gide collagen membrane especially suitable for handling wide root canals.

Radiographic outcome of necrotic immature teeth treated with two endodontic techniques: A retrospective analysis.

BACKGROUND: The endodontic treatment of teeth with immature root has always been a challenge. To achieve a better prognosis, regenerative endodontic treatment may become a treatment trend for teeth with apical periodontitis and immature roots. METHODS: Clinical and radiographic data were collected from 38 endodontic treated immature teeth (21 apexification and 17 regeneration). Measure the radiographic outcome by quantifying the apical lesion. RESULTS: There was no statistical difference between the two treatments regarding PAI scores at the 1-, 3-, 6-, and 12-month follow-up (p > 0.05). In addition, different operators and the different stages of root development for both techniques showed no significant statistical difference on the final treatment results. CONCLUSIONS: In this study, assessment of the radiographic outcomes indicated that regenerative endodontic treatment were identical to the apexification technique.

Arsenic trioxide-induced osteo-necrosis treatment in a child: mini-review and case report.

BACKGROUND: Arsenic oxide compounds were traditionally used as devitalizing agents. Due to its toxicity, leakage of such compounds into the periodontium can cause gingival and osteo-necrosis. Their use is forbidden in Europe and the USA for decades, however, some dentists seem to still use it. CASE REPORT: We report the case of a 14-year-old girl referred to the paediatric dentistry department of Toulouse University hospital, France, presenting a bone necrosis following the use of an arsenic trioxide product to accelerate pulp necrosis. TREATMENT: The treatment included surgical removal of necrosis bone sequestrum, complete pulpectomy and an intermediate restoration of the tooth 27. FOLLOW-UP: After 1 week, the clinical conditions greatly improved. A restoration using a ceramic crown was performed after 2 months, and complete healing was observed after 1 year follow-up. CONCLUSION: Although arsenic trioxide is neither appropriate nor permitted for use in modern dentistry, especially in paediatric dentistry, some rare cases of arsenic-induced osteo-necrosis can still be encountered. A clearer message must be given to all dental practitioners against the use of arsenic trioxide in modern endodontic treatment.

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.