ABSTRACT Objective: The purpose of the present in vitro study was to evaluate the efficiency of three different instruments in the root canals of artificial primary molars as well as the quality of the fillings. Methods: Sixty artificial primary molars were divided into three groups of 20 teeth. Each group was submitted to a different technique: Group 1 - conventional manual technique using Kerr files; Group 2 - manual technique with nickel-titanium files; Group 3 - NiTi rotary technique. The root canals were filled with calcium hydroxide paste. Aspects such as homogeneity of the fillings, taper and flowability of the preparations were considered comparatively to assess the quality of the instrumentations. The non-parametric Kruskal-Wallis and Mann-Whitney tests were used to compare the efficiency of the preparation of the root canal considering the preparation times of them. Results: All three techniques were equally effective at shaping the root canals of primary teeth. The working time was shorter with the rotary instrument (p=0.000). In the pairwise comparisons, working time was shorter with the rotary instrument compared to the manual techniques with steel files (p=0.000) and NiTi files (p=0.000). Comparing the manual techniques, the working time was shorter with NiTi files compared to steel files (p=0.011). Moreover, less variability in the preparation time was found when the rotary instrument was used. Conclusions: The mechanized rotary method led to a shorter operating time in comparison to the manual techniques and is therefore a preferable option for the preparation of the root canals of primary teeth.

RESUMO Objetivo: Avaliar a eficiência de três instrumentos diferentes nos canais radiculares de molares decíduos artificiais, bem como a qualidade das obturações. Métodos: Sessenta molares decíduos artificiais foram divididos em três grupos de 20 dentes. Cada grupo foi submetido a uma técnica diferente: Grupo 1 - técnica manual convencional com limas Kerr; Grupo 2 - técnica manual com limas de níquel-titânio; Grupo 3 - Técnica rotatória de níquel-titânio. Os canais radiculares foram preenchidos com pasta de hidróxido de cálcio. Aspectos como homogeneidade das obturações, conicidade e fluidez das preparações foram considerados comparativamente para avaliar a qualidade das instrumentações. Os testes não paramétricos de Kruskal-Wallis e Mann-Whitney foram utilizados para comparar a eficiência do preparo do canal radicular considerando os tempos de preparo dos mesmos. Resultados: Todas as três técnicas foram igualmente eficazes na modelagem dos canais radiculares. O tempo de trabalho foi menor com o instrumento rotatório (p=0,000). Nas comparações pareadas, o tempo de trabalho foi menor com o instrumento rotatório em comparação com as técnicas manuais com limas de aço (p=0,000) e limas de NiTi (p=0,000). Comparando as técnicas manuais, o tempo de trabalho foi menor com as limas de NiTi em comparação com as limas de aço (p=0,011). Além disso, foi encontrada menor variabilidade no tempo de preparo quando o instrumento rotatório foi utilizado. Conclusão: O método rotatório levou um menor tempo operatório em comparação com as técnicas manuais e, portanto, é uma opção preferível para o preparo dos canais radiculares de dentes decíduos.

RESUMO A fusão dentária é classificada como uma alteração de desenvolvimento referente à união de dois germes dentários, podendo incluir coroa, raiz e polpa. Este tipo de alteração ocorre durante o desenvolvimento intraósseo, resultando em um dente morfologicamente irregular, podendo acometer tanto a dentição decídua quanto a permanente. Frequentemente são associados problemas clínicos como alterações estéticas, falta de espaço e maior susceptibilidade a lesões cariosas. É importante ressaltar que a fusão é comumente confundida com a geminação dentária, que apresenta o mesmo aspecto clínico em boca, porém é resultante de um único germe dentário. O objetivo deste estudo é apresentar um caso clínico de fusão de dois incisivos inferiores decíduos, as perspectivas de tratamento da anomalia e discutir sua repercussão durante o desenvolvimento da dentição. Realizou-se a exodontia do elemento citado e o planejamento do tratamento ortodôntico recomendado foi discutido visando a melhora dos aspectos funcional e estético. Um planejamento integrado entre a Odontopediatria e Ortodontia proporcionou uma melhor alternativa de tratamento.

ABSTRACT Fused teeth are a developmental anomaly involving the union of two dental germs at the crown, root or pulp. This type of anomaly occurs during intraosseous development, resulting in a morphologically irregular tooth that can affect both the primary and permanent dentition. Clinical problems involving esthetics, a lack of space and greater susceptibility to caries are often associated with fused teeth. This type of anomaly is easily confused with dental twinning, which has similar clinical features but emerges from a single dental germ. The aim of the present study was to report a clinical case of the fusion of two deciduous mandibular incisors, describe prospects for treating this anomaly and discuss its repercussions during the development of the dentition. Extraction of the fused tooth was performed and orthodontic treatment was recommended for esthetic and functional improvements. Integrated planning involving both Pediatric Dentistry and Orthodontics provided a better treatment option.

Abstract Objective: To discover the perceptions of pediatric patients, their parents and undergraduate Dentistry students of the use of the diode laser in frenectomy surgeries. Material and Methods: A qualitative study was conducted through semi-structured interviews, recorded and transcribed with subsequent content analysis. Twelve healthy children (5-8 years old) who needed a frenectomy were selected and invited, together with their parents, to undergo laser diode surgery. In addition, 28 undergraduate dentistry students were invited to attend the procedures. One week after performing the surgical procedures, the children (Group 1), their parents (Group 2) and the students who attended the procedures (Group 3) were individually interviewed for the thematic analysis. Results: The analysis of the conversations identified three emerging contents: positive thoughts on the use of diode laser; frustrations from the use of diode laser; and aspects related to professional training. Conclusion: The results pointed to the acceptance of surgical laser use in pediatric dentistry; however, the feelings of frustration indicate that its use requires guidance from the child and his/her parents, in addition to careful handling and specific training.

Abstract Objective: To evaluate the Antimicrobial Photodynamic Therapy (aPDT) in infected deciduous teeth by quantifying the viable bacteria in root canal treatment. Material and Methods: Radicular canal cultures were collected (n= 10). Four intra-canal samples were collected at four different times in each of the sampled teeth, as follows: Time 1 (T1), baseline: After opening the pulp-chamber; Time 2 (T2): After application of aPDT; Time 3 (T3): After mechanical, chemical manipulation; Time 4 (T4): After a second application of aPDT. The aPDT was performed with a 4J/cm energy low-intensity diode, together with 0.005% methylene blue as a photosensitizer. The clinical specimens were taken to the laboratory for a bacteria count (colony forming units) and the results were statistically analyzed using the Friedman and Wilcoxon tests, with a significance level of α=0.05. Results: Statistical differences were seen between the numbers of bacteria at times T1-T2, T1-T3 and T1-T4 on the cultivated plates. However, no significant statistical differences were observed between the number of bacteria in samples T2-T3, T2-T4 and T3-T4. Conclusion: Antimicrobial photodynamic therapy can be a good co-adjuvant in root canal decontamination of necrotic primary teeth.