Eficácia entre dois localizadores apicais eletrônicos testados no nível do forame e ultrapassando e retornando ao forame / Effectiveness between two electronic apex locators tested at foramen level and passing through and returning to the foramen

Introdução: O localizador apical eletrônico é uma ferramenta que facilita o tratamento endodôntico. O objetivo do presente estudo foi avaliar, in vitro, a precisão de dois localizadores apicais usados de duas maneiras distintas. Material e métodos: As medidas reais de 20 molares inferiores extraídos de humanos foram determinadas, posicionando-se os instrumentos até o forame, auxiliados por um microscópio clínico com 20x de aumento. As medidas foram realizadas com um paquímetro. Feito isso, os dentes foram montados em uma plataforma de polietileno, posicionada dentro de uma cuba plástica contendo gelatina preparada com soro fisiológico e, então, as medidas eram realizadas com os localizadores Novapex e Root ZX, posicionando os instrumentos na posição zero ou passando com o instrumento além do zero e voltando a essa posição. Para a análise dos resultados foi usada a diferença das duas medidas (real do dente e obtida pelo aparelho). Resultados: Os dados das raízes distais e mesiais foram submetidos à análise estatística. Na raiz distal o teste Anova mostrou diferença significante entre os grupos (p<0,01) e o teste de Tukey demonstrou diferença entre os valores do Novapex passando e do Root ZX na posição zero. Na raiz mesial, o teste Anova não mostrou diferença significante entre os grupos (p>0,01). Conclusão: Conclui-se que quando se usou a técnica de ir até o zero, o aparelho Novapex mostrou-se mais preciso, porém na técnica de passar e retornar ao zero, o aparelho mais preciso foi o Root ZX (AU)

Introduction: The electronic apex locator is a tool that facilitates endodontic treatment. The aim of this study was to evaluate in vitro the accuracy of two apex locators used in two different ways. Methods: Real measurements of 20 lower molars extracted from human were determined by positioning the instruments until the foramen aided by a 20x clinical microscope. The measurements were taken with a caliper. After this, the teeth were mounted on a polyethylene platform, positioned inside a plastic tub containing gelatin prepared with saline and the measures were carried out with the locators Novapex and Root ZX positioning instruments in zero or passing with the instrument beyond zero and returning to this position. The difference between the two measurements (real tooth and obtained by the device) were used for results analysis. Results: Data from the distal and mesial roots were subjected to statistical analysis. In the distal root, ANOVA showed significant difference between groups (p <0.01) and Tukey's test showed difference between the Novapex values ​when passing and Root ZX in zero. At the mesial root, ANOVA showed no significant difference between groups (p> 0.01). Conclusion: It was concluded that when using the technique positioning instruments in zero the Novapex was more accurate, however when the technique was to pass and to return to zero, the most accurate device was the Root ZX (AU)

Avaliação da capacidade de dissolução de tecido pulpar bovino pelo hipoclorito de sódio em diferentes concentrações / Pulp tissue dissolution capacity of sodium hypochlorite in different concentrations

Introdução: O hipoclorito de sódio é a substância química auxiliar do tratamento endodôntico mais utilizada devido à sua ação antimicrobiana e à sua capacidade de dissolver matéria orgânica. Objetivo: O objetivo do presente estudo foi comparar a velocidade de dissolução de fragmentos de tecido pulpar bovino em diferentes concentrações de hipoclorito de sódio. Material e método: Fragmentos de tecido pulpar bovino, com peso determinado, foram imersos em 20 mL de hipoclorito de sódio, em frascos de Becker colocados em uma incubadora/agitadora. Foram testadas as concentrações de 1%, 2,5% e 5%, com pH 11, a 36°C. As amostras foram avaliadas visualmente durante a agitação, com auxílio de lupa, até sua completa dissolução. A velocidade de dissolução de cada fragmento foi determinada em miligramas por minuto e a velocidade média de cada grupo, analisada pelos métodos estatísticos de Kruskal-Wallis e Dunn's Multiple. Resultado: Houve diferença estatisticamente significante entre a concentração de 1%, que apresentou a menor velocidade, e as demais. Conclusão: A velocidade de dissolução do hipoclorito de sódio, nas concentrações testadas, se torna mais rápida com o aumento da concentração.

Introduction: sodium hypochlorite is the most used auxiliary chemical substance in endodontic treatment due to its antimicrobial action and its ability to dissolve organic matter. Objective: the objective of the present study was to compare the dissolution speed of bovine pulp tissue fragments in different concentrations of sodium hypochlorite. Material and method: bovine pulp tissue fragments, with determined weight, were immersed in Becker bottles filled with 20 ml of sodium hypochlorite and placed in an incubator/stirrer. Concentrations of 1%, 2.5% and 5%, with pH of 11, at 36°C. Each sample was evaluated visually during the stirring, with the aid of magnifying glass, until its complete dissolution. The speed of dissolution of each fragment was determined in milligrams per minute and by the average speed of each group was analyzed by Kruskal-Wallis and Dunn's Multiple statistical methods. Result: There were statistically significant differences between the concentration of 1%, with the lowest speed, and others. Conclusion: The dissolution speed of sodium hypochlorite of tested concentrations, becomes faster with the increasing of the concentration.

Evaluation of four gutta-percha removal techniques for endodontic retreatment

Introduction: The endodontic retreatment is the first choice in cases of endodontic treatment failure. Objective: To evaluate the ability of removing gutta-percha from root canal walls, through analyzing the time and different techniques. Material and methods: Sixty extracted human mandibular pre-molars were used. After instrumentation with crown-down technique, the obturation was performed by Tagger's hybrid technique. The specimens were divided into 4 groups (n = 15), according to removal procedure: group I (manual + solvent), group II (manual + Gates-Glidden + solvent), group III (Protaper Universal Retreatment System) and group IV (Protaper Universal System + solvent). The time period for gutta-percha removal was measured with a stopwatch. The roots were sectioned and the remnants were visually evaluated, according to the following scores: 0 - without remnant, 1 - presence of only cement, 2 - presence of cement and gutta-percha in small amounts, and 3 - presence of cement and gutta-percha in large amounts. Data were statistically evaluated with the GraphPad InStat software. Results: Group II exhibited the shortest time of execution, with significant differences in relation to groups I and IV, which obtained the longest time periods. Group III showed an intermediate time period, with statistically significant differences in relation to group IV. Group IV obtained the best scores of cleaning, although there was no statistical difference among groups. Conclusion: There was no statistical significant difference among the techniques regarding the time and effectiveness in removing filling material from the root canal walls.

Fratura radicular horizontal – relato de caso / Horizontal root fracture – case report

O objetivo do presente trabalho ‚ relatar um caso de fratura radicular horizontal tratada com Ca(OH) 2 e obturada com MTA. Paciente do sexo feminino, 20 anos, apresentou-se para tratamento queixando-se de dor e discreta mobilidade no dente 21. A paciente relatou ter sofrido uma queda há 2 meses e batido a boca. No exame clínico, observou-se que o dente 21 apresentava discreta mobilidade e alteração de cor, dor moderada na percussão vertical e horizontal, ausência de vitalidade pulpar, aspecto e coloração gengival normais, ausência de deslocamento da porção coronária e coroa do dente hígida. O exame radiográfico revelou fratura horizontal no terço médio desta raiz. Foi realizado o tratamento endodêntico do segmento radicular coronário … linha de fratura, sendo o canal radicular esvaziado, modelado e preenchido com Ca(OH) 2 a 1 mm aquém da linha de fratura. Este foi trocado com intervalos trimestrais até completar 1 ano e 3 meses. Com o auxílio de um microscópio clínico, foi realizado o preenchimento total do segmento radicular coronário … linha de fratura com MTA. Após 20 meses, o dente encontra-se assintomático e, radiograficamente, com presença de lâmina dura e ausência total de infecção. Concluiu-se que o MTA ‚ viável para obturação do remanescente coronário em um caso de fratura do terço médio radicular

The aim of this study was to report a case of horizontal root fracture treated with Ca(OH)2 and filled with MTA. The patient, a 20 year-old woman, presented for treatment complaining of pain and discrete mobility of tooth 21. The patient reported that she hit her mouth on an accidental fall 2 months before. During intra-oral examination it was observed that the tooth 21 presented discrete mobility and color alteration, moderate pain on vertical and horizontal percussion, negative response to vitality test, normal gingival aspect and coloring, no displacement of coronal portion, and the crown was healthy. Radiographic examination showed horizontal fracture in the middle third of this root. Access cavity and chemical-mechanical preparation were performed to 1 mm short of the fracture line, and Ca(OH) 2 was used for intra-canal dressing. Using a clinical microscope, the coronal portion of the canal was filled with MTA. After 20 months the tooth is asymptomatic; radiograph showed complete healing between the fragments with no infection. It was concluded that MTA filling can be an alternative to the routine treatments of horizontal root fracture in the middle third

O uso dos protetores bucais na prática do basquete / The use of mouthguards in basketball practice

O uso dos protetores bucais durante a prática esportiva visa proteger os atletas contra as injúrias dentofaciais. Este estudo tem o objetivo de analisar, mediante um questionário que foi aplicado em jogadores de basquete, se há ou não o uso dos protetores durante a prática do esporte, e se eles sabem como agir frente … avulsão dentária. Foi aplicado um questionário para 67 jogadores de basquete de ambos os sexos. As questões incluíam tempo de prática do esporte; ocorrência de alguns traumas; se faz o uso do protetor, e qual; se conhece a importância do uso dos protetores; se o seu técnico já  mencionou sobre o uso dos protetores; se o seu dentista sabe que ele pratica o esporte e se já  comentou sobre a importância do uso do protetor. Constatou-se que a maioria dos entrevistados (63%) joga basquete há  mais de 3 anos e, destes, 70,15% nunca sofreram traumatismo. Apenas dois atletas relataram fazer uso do protetor bucal. 79,10% relataram que seus dentistas sabiam de sua prática esportiva sendo que somente 49,25% recomendavam a utilização de protetores bucais. Embora 29,85% dos entrevistados já  tinham sofrido traumatismo e 76,11% dos atletas relataram ter consciência da importância do uso do protetor bucal, o seu uso ainda‚ restrito a 3% dos entrevistados. Com os resultados obtidos neste estudo pode-se afirmar que os jogadores de basquete não usam o protetor bucal mesmo conhecendo a sua importância, e não sabem como agir frente … avulsão dentária

The use of mouthguards during sports practice aims to protect athletes against dentofacial injuries. The aim of this study was to evaluate the percentage of basketball athletes that uses mouthgards and their knowledge on dental avulsion. Therefore a questionnaire was applied to 67 basketball players of both genders. The questions covered aspects such as the time dedicated to the practice of this sport; the occurrence of trauma; the use of the protector, if the dentist is aware that the athlete practices basketball and if has commented on the importance of using mouthguards. It was found that the majority of respondents (63%) have being playing basketball for over three years and 70.15% of them have never suffered any trauma. Only two athletes reported use of mouthguard, and 79.10% reported that their dentists was informed about their sport practice. However just 49.25% recommended the use of mouthguards. Even though 29.85% of the athletes had suffered trauma and 76.11% of them reported being aware of the importance of using a mouthguard, the use of these protectors are still restricted to 3% of the sample. According to these results it can be stated that basketball players do not wear a mouthguard, even knowing its importance, and do not know how to act in the presence of dental avulsion

Avaliação in vivo do localizador apical Novapex na determinação do comprimento do dente / In vivo evaluation of Novapex apex locator in determining the length of the tooth

O objetivo deste estudo é avaliar, in vivo, a confiabilidade do localizador apical Novapex na determinação do comprimento do dente, submetido ao tratamento endodôntico. Foram avaliados um total de 29 canais de 15 pacientes com indicação endodôntica. Os dentes foram anestesiados e isolados com dique de borracha, seguidos da abertura coronária, acesso radicular e exploração do canal com lima # 15. A Odontometria foi realizada utilizando-se o localizador apical com uma lima ajustada ao diâmetro do canal, que foi introduzida até o aparelho acusar a escala 0 do visor (forame). O dente foi radiografado com a lima nessa medida e as radiografias foram digitalizadas e analisadas no programa Image Toll versão 3.00 para que os comprimentos em mm da distância entre o ápice radiográfico e a ponta da lima fossem mensurados. Os resultados demonstraram que o localizador apical registrou a posição do instrumento entre 0 a 1mm em 24 canais (82,75%), sendo que em 6 canais (20,68%) as medidas ficaram exatamente no zero. Em 4 canais (13,79%) observou-se, radiograficamente, o transpasse do instrumento pelo forame radiográfico, porém em 3 canais o valor foi menor que 0,5mm. Medidas compreendidas entre 0 e 1mm foram consideradas ideais. O localizador apical Novapex mostrou ser seguro, prático e confiável, porém, ainda carente de uma radiografia de confirmação.

The objective of this study was to evaluate in vivo the reliability of Novapex apex locator in determining the length of tooth submitted to endodontic treatment. A total of 29 channels of 15 patients referred to endodontics, were evaluated. Teeth were anesthetized and isolated with rubber dam, followed by coronal opening, root access and exploration of the canal with file # 15. The Odontometry was performed using the apex locator with a file adjusted to the diameter of the canal. The instrument was introduced until show scale 0 of the display (foramen). The tooth was radiographed with the file inn this position and radiographs were digitized and analyzed in the Image Toll version 3.00 program to measure the length in mm of the distance between the radiographic apex and the tip of the file. Results showed that the apex locator registered the position of the instrument between 0 and 1mm in 24 canals (82.75%), and for 6 canals (20.68%) the measures were exactly at zero. Through radiographs was observed on 4 canals (13.79%) the overlapping of the instrument by radiographic foramen, but for 3 of them the value was lower than 0.5mm. Measures between 0 and 1mm were considered ideal. The Novapex apex locator has is safe, practical and reliable. However it still requires confirmation by radiographic exam.

Effects of 980-nm diode laser on the ultrastructure and fracture resistance of dentine.

Few reports have addressed the effects of diode laser irradiation at 980 nm on the morphology and fracture resistance of dentine. The purpose of this study is to evaluate the effects of 980-nm diode laser on the ultrastructure and fracture resistance of root dentine. The roots of 90 extracted canine teeth were divided into three groups according to the type of irrigating solution (water, NaOCl, and NaOCl/EDTA) and subdivided into three subgroups (n = 10) according to the amount of laser irradiation (without irradiation, 1.5 W/100 Hz and 3.0 W/100 Hz). The roots were filled with an epoxy resin-based sealer and gutta-percha and then subjected to a fracture resistance test. Data were analyzed by ANOVA and the Tukey test (p < 0.05). Additionally, 18 canine teeth were prepared using the same irrigation/irradiation protocols and evaluated by scanning electron microscopy (SEM). The SEM showed greater changes when the laser power increased, and the changes also varied according to the irrigating solution. A modified smear layer was observed in specimens that were treated with water and then laser-irradiated. The laser treatment did not alter the fracture resistance of roots treated with 1.5 W/100 Hz (246.3 ± 29.5 N) and 3.0 W/100 Hz (215.3 ± 25.1 N) laser power. The roots treated with NaOCl were more susceptible to fracture (199.4 ± 15.1 N) than those irrigated with water (254.2 ± 23.0 N) (p < 0.05). The 980-nm diode laser altered the morphology of the dentine but did not affect the fracture resistance of the roots.

Apical microleakage and SEM analysis of dentin surface after 980 nm diode laser irradiation.

This study evaluated the effect of 980-nm diode laser on apical microleakage and intraradicular dentin morphology. Roots of 110 mandibular incisors were used in the study: 92 for microleakage test and 18 for scanning electron microscopy (SEM). Roots were randomly assigned to 3 groups according to the irrigating solution (water, NaOCl and NaOCl/EDTA) and were divided into 3 subgroups according to the laser irradiation protocol (without irradiation, irradiated at 1.5 W and irradiated at 3.0 W). Two specimens of each subgroup were prepared for SEM. The remaining roots were filled with AH Plus and gutta-percha. Apical leakage was assessed by ink penetration and data were analyzed statistically by ANOVA and Tukey-Krammer test (α=0.05). SEM analysis showed intensification of changes with increase of laser power as well as variations according to the irrigating solution. Modified smear layer was observed in specimens treated with water and irradiated with laser. Roots irrigated with NaOCl/EDTA had lower levels of infiltration (0.17 ± 0.18 mm) differing significantly (p<0.05) from those of roots irrigated with water (0.34 ± 0.30 mm), but similar (p>0.05) to those irrigated with NaOCl (0.28 ± 0.29 mm). Non-irradiated roots had lower levels of infiltration (0.10 ± 0.14 mm), differing (p<0.05) from those irradiated at 1.5 W (0.32 ± 0.22 mm) and 3.0 W (0.37 ± 0.32 mm). The 980 nm diode laser modified dentin morphology and increased apical microleakage.

Retratamento endodôntico: análise comparativa da efetividade da remoção da obturação dos canais radiculares realizada por três métodos / Endodontic retreatment: gutta-percha removal by three different techniques

OBJETIVO: Analisar comparativamente a efetividade da remoção da obturação dos canais radiculares realizada por três métodos. MÉTODOS: Trinta caninos humanos extraídos foram instrumentados e obturados com cones de guta-percha e cimento Endofill (Dentsply-Maillefer, Petrópolis, Brasil) pela técnica híbrida de Tagger. Após radiografias nos sentidos mésio-distal e vestíbulo-lingual foram divididos em três grupos de acordo com a remoção da guta-percha: Grupo I) brocas de Gates-Glidden associadas a limas Flexofile (Maillefer, Ballaigues, Suíça) e solvente; Grupo II) sistema rotatório Profile.04 (Maillefer, Ballaigues, Suíça); e Grupo III) brocas de Gates-Glidden associadas ao sistema Profile e solvente. Concluída a desobturação todos os dentes foram radiografados. As radiografias, antes e depois da desobturação, foram digitalizadas e o software AutoCAD foi utilizado para delimitar e quantificar as áreas do canal com material obturador antes e após a desobturação. RESULTADOS: Os dados foram submetidos ao teste estatístico ANOVA que mostrou haver diferença estatisticamente significante entre os grupos. O teste de Tukey revelou diferença significativa entre o Grupo I, com maior quantidade de material obturador removido e o Grupo II, que removeu menor quantidade. CONCLUSÃO: Concluiu-se que nenhuma técnica foi capaz de remover completamente o material obturador dos canais; e que no terço apical, independente da técnica, os dentes apresentaram uma maior quantidade de resíduos após a desobturação.

OBJECTIVE: A comparative analysis was made to determine how efficiently three different techniques can remove endodontic fillings from root canals. METHODS: Thirty human extracted canines were prepared and filled with gutta-percha cones and Endofill (Dentsply-Maillefer, Petrópolis, RJ, Brazil) sealer, according to Tagger's technique. After mesiodistal and buccolingual radiographs, the canines were divided into three groups according to removal technique: Group I) Gates-Glidden burs associated with Flexofile (Maillefer, Ballaigues, Switzerland) files and a solvent; Group II) rotary Profile.04 (Maillefer, Ballaigues, Switzerland) system; and Group III) Gates-Glidden burs with solvent and rotary Profile.04 system. Once the fillings were removed, the teeth were once again radiographed. The radiographs before and after filling removal were scanned and the software AutoCAD was used to define and quantify the filled areas of the root canal before and after filling removal in the cervical, middle and apical thirds. RESULTS: Analysis of variance showed a statistically significant difference between the groups. The Tukey's test revealed a significant difference between Group I, which presented the best filling removal and Group II, which presented the worst filling removal. CONCLUSION: None of the techniques were capable of completely removing the fillings from the root canals. The apical third presented the greatest amount of leftover filling material, regardless of technique.

Apical microleakage and SEM analysis of dentin surface after 980 nm diode laser irradiation

This study evaluated the effect of 980-nm diode laser on apical microleakage and intraradicular dentin morphology. Roots of 110 mandibular incisors were used in the study: 92 for microleakage test and 18 for scanning electron microscopy (SEM). Roots were randomly assigned to 3 groups according to the irrigating solution (water, NaOCl and NaOCl/EDTA) and were divided into 3 subgroups according to the laser irradiation protocol (without irradiation, irradiated at 1.5 W and irradiated at 3.0 W). Two specimens of each subgroup were prepared for SEM. The remaining roots were filled with AH Plus and gutta-percha. Apical leakage was assessed by ink penetration and data were analyzed statistically by ANOVA and Tukey-Krammer test (α=0.05). SEM analysis showed intensification of changes with increase of laser power as well as variations according to the irrigating solution. Modified smear layer was observed in specimens treated with water and irradiated with laser. Roots irrigated with NaOCl/EDTA had lower levels of infiltration (0.17 ± 0.18 mm) differing significantly (p<0.05) from those of roots irrigated with water (0.34 ± 0.30 mm), but similar (p>0.05) to those irrigated with NaOCl (0.28 ± 0.29 mm). Non-irradiated roots had lower levels of infiltration (0.10 ± 0.14 mm), differing (p<0.05) from those irradiated at 1.5 W (0.32 ± 0.22 mm) and 3.0 W (0.37 ± 0.32 mm). The 980 nm diode laser modified dentin morphology and increased apical microleakage.

Este estudo avaliou o efeito do laser de diodo 980 nm na microinfiltração apical e na morfologia intrarradicular da dentina. Raízes de 110 incisivos inferiores foram utilizadas no estudo: 92 para o teste de microinfiltração e 18 para microscopia eletrônica de varredura (MEV). As raízes foram divididas em 3 grupos de acordo com a solução irrigante (água, NaOCl e NaOCl/EDTA) e subdivididas em 3 de acordo com a irradiação laser (sem irradiação, irradiados com 1,5 W e irradiados com 3,0 W). Duas amostras de cada subgrupo foram preparadas para MEV. As raízes restantes foram preenchidas com AH Plus e guta percha. A infiltração apical foi avaliada nas raízes por meio da penetração do corante e os dados foram analisados por ANOVA e teste de Tukey-Krammer (α=0,05). Os resultados da MEV mostraram intensificação das mudanças quando se aumentou a potência do laser e variações de acordo com a solução irrigadora. Camada de smear modificada foi observada em espécimes tratados com água e irradiados com laser. Raízes irrigadas com NaOCl/EDTA tiveram níveis menores de infiltração (0,17 ± 0,18 mm) estatisticamente diferente (p<0,05) das raízes irrigadas com água (0,34 ± 0,30 mm), mas semelhante (p>0,05) aos irrigados com NaOCl (0,28 ± 0,29 mm). As raízes não irradiadas tiveram níveis menores de infiltração (0,10 ± 0,14 mm), diferente (p<0,05) de 1,5 W (0,32 ± 0,22 mm) e 3.0 W (0,37 ± 0,32 mm). O laser de diodo 980 nm alterou a morfologia da dentina e aumentou a infiltração marginal apical.

Endodontic treatment of dental formation anomalies / Tratamento endodôntico de anomalia dental de formação

PURPOSE: Dental fusion is defined as the union of two dental germs at some stage of their development. The aim of this article is to report the endodontic treatment of two clinical cases of dental fusion. CASE DESCRIPTION: In the first case, the patient was referred by an orthodontist for endodontic treatment of tooth 12, which was fused to 13. Surgical separation and later replacement of the involved elements in the dental arch was indicated. In the second case, the patient sought dental attendance due to spontaneous pain. In the radiographic exam, gemination in tooth 11 and fusion of 21 with a supernumerary tooth was observed. The fused teeth were endodontically treated, and patients were referred to other dental specialties to reestablish esthetics and function. CONCLUSION: The dentist must be able to diagnose, differentiate and treat these dental anomalies adequately, with the goal of maintaining patients' oral health.

OBJETO: Fusão dental é definida como sendo a união de dois germes dentais em algum momento do estágio de desenvolvimento. O objetivo desse artigo foi descrever o tratamento endodôntico de dois casos de fusão dental. DESCRIÇÃO DO CASO: No primeiro caso clínico, o paciente foi orientado pelo ortodontista a realizar tratamento endodôntico do dente 12, o qual estava fusionado ao dente 13. Foi realizada a separação cirúrgica dos elementos dentais e posterior reposicionamento no arco dental. No segundo caso clínico, o paciente procurou atendimento relatando dor espontânea na região anterior superior. Por meio do exame radiográfico, foi observado geminação do dente 11 e fusão do dente 21 com dente extranumerário. Em ambos os casos os dentes fusionados foram tratados endodônticamente e os pacientes encaminhados para restabelecimento da estética e função. CONCLUSÃO: O cirurgião dentista deve ter habilidade de diagnosticar, diferenciar e tratar adequadamente as anomalias dentárias, objetivando a manutenção da saúde oral dos pacientes.

Knowledge and attitudes toward dental avulsion of public and private elementary schoolteachers.

PURPOSE: The purpose of this study was to evaluate and compare the knowledge and attitudes toward dental avulsion of public and private elementary schoolteachers. METHODS: the study was performed by applying a questionnaire in a sample composed of 95 elementary schoolteachers (46 from public schools and 49 from private schools). The questionnaire comprised 9 questions and was pretested before final implementation. RESULTS: Thirty-nine percent of private schoolteachers and 15% of public schoolteachers witnessed at least 1 case of dental avulsion at the school (P=.009). Ninety-two percent and 62% of private and public schoolteachers, respectively, admitted the possibility of an avulsioned tooth to be reimplanted (P<.001). Both responses were statistically different when school type (public or private) was considered. Only 27% of private schoolteachers and 11% of public schoolteachers knew the procedures to be taken in cases of avulsed teeth, and more than 95% of all teachers did not feel capable of executing tooth reimplantation. The study showed no statistical difference between private and public schoolteachers' knowledge. CONCLUSIONS: Teachers and other professionals involved in children's care and supervision must be correctly and well informed about dental avulsion, its consequences and the correct procedures to be performed in such cases.

Ultrastructural evaluation of radicular dentin after Nd:YAG laser irradiation combined with different chemical substances.

This aticle sought to evaluate the dentin morphology after irradiation by a Neodymium:Yttrium-Aluminum-Garnet (Nd:YAG) laser, using different chemical substances to irrigate radicular canals: distilled water, 17% ethylenediaminetetraacetic acid plus Cetavlon (EDTAC), 1% sodium hypochlorite, and 2% chlorhexidine. Groups were subdivided according to the protocol of laser application (n=9). The specimens were analyzed by scanning electron microscopy (SEM). No differences were found in dentin morphology when different root thirds were examined. Regardless of the chemical substance used, alterations were more evident in groups in which the surfaces were dried before laser irradiation. Fusion areas, craters, carbonization, and partially exposed tubules were verified. When the irradiation was performed in water, the smear layer was incorporated into the laser-modified surface. Among the specimens irrigated with EDTAC and laser-treated, partial obliteration of dentin tubules due to the laser action was verified; in addition, there was no remaining smear layer on the surfaces. Samples irrigated with sodium hypochlorite followed by laser irradiation demonstrated similar morphology to the samples in the chlorhexidine group, with some fusion areas present and no exposed dentin tubules or fissures. The irradiation from an Nd:YAG laser in the presence of EDTAC solution provided a more favorable surface pattern compared to the other experimental conditions, due to the removal of the contaminated layer and the posterior sealing of dentin tubules.