Endodontic techniques with Nickel Titanium instruments: analysis of quality and efficiency of instrumentation in primary molars / Técnicas endodônticas com instrumentos de Níquel Titânio: análise da qualidade e eficiência da instrumentação em molares decíduos

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.

Agreement Between Working Length Measurements in Primary Teeth Obtained by Radiographs or Apical Locators

Abstract Objective: To perform an in vivo evaluation on the agreement between measurements of working length obtained by conventional radiographic examinations and an apex locator in deciduous teeth with or without root resorption. Material and Methods: Nine canals of teeth from children ranging from 3 to 5 years old were selected. Endodontic access was performed with a spherical diamond tip, the pulp was removed with Kerr-type steel files, and the canal was irrigated with 1% sodium hypochlorite. A file, compatible with the channel gauge, was then used to measure the length of the root canal with the apex locator. Conventional radiographs were also performed and, using a millimeter endodontic ruler, the length of the canal was determined. The differences between the measurements obtained between the two methods were analyzed using the Student's t-test. Results: The mean canal length for conventional radiography was 9.83 mm and 9.67 mm for the apex locator. The results of this study did not show significant differences (p=0.641), independent of the presence or absence of physiological root resorption. Conclusion: The similarity in measurements obtained with X-ray or an apex locator indicates that it is not necessary to use X-rays as a complement to obtain the working length. The use of the apex locator can provide a quicker treatment, reducing the clinical time and stress of the child.

Antimicrobial Photodynamic Therapy in the Endodontic Treatment of Deciduous Teeth: In Vivo Pilot Study

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.

Perceptions of the Use of the Diode Laser in Dental Surgery: A Qualitative Study

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.

Oral health-related quality of life of children and teens with sickle cell disease

BACKGROUND: Children with sickle cell disease may have their quality of life affected by oral alterations. However, there is still little data on oral health-related quality of life in these children. The aim of this study was to investigate the influence of sickle cell disease, socioeconomic characteristics, and oral conditions on oral health-related quality of life of children and teens. METHOD: One hundred and six children and teens with sickle cell disease were compared to a similar sample of 385 healthy peers. Data were collected through oral examinations, interviews to assess quality of life (Child Perceptions Questionnaire for children aged 8-10 and 11-14) and questionnaires containing questions on socioeconomic status. RESULTS: There were no statistically significant differences in the total scores of the Child Perceptions Questionnaires or domain scores comparing sickle cell disease patients to control subjects. When sub-scales were compared, oral symptoms and functional limitations had a greater negative impact on the quality of life of adolescents with sickle cell disease (p-value <0.001 and p-value <0.01, respectively) when compared to healthy controls. The only statistically significant determinants of negative impact on oral health-related quality of life in the overall sample was home overcrowding (more than two people/room) in the younger children's group, and dental malocclusion among teens. CONCLUSION: There was no significant difference in the negative impact on the oral health-related quality of life between the group with sickle cell disease and the control group. Of the oral alterations, there was a significant difference in the oral health-related quality of life between adolescents with sickle cell disease and controls only in relation to malocclusion. Among the socioeconomic characteristics, only overcrowding was significantly associated with a negative impact on oral health-related quality of life.

Expressão da Osteopontina após utilização de matriz dentinária humana desmineralizada em alvéolos de ratos: análise imunohistoquímica / Osteopontin expression after use of demineralized human dentin matrix in rats alveoli: immunohistochemistry analysis

Apesar de sua capacidade de reparo, o tecido ósseo pode ser submetido a alguns tipos de fraturas, cirurgias ou patologias que podem levar a grandes defeitos ósseos. As principais estratégias de tratamento de defeitos ósseos são baseados em osteoindução ou osteocondução. Matriz dentinária desmineralizada humana (MDDH) é uma alternativa biocompatível para preencher defeitos ósseos, melhorando a qualidade e quantidade de osso produzido. 24 Ratos Wistar foram selecionados, submetidos à extração de ambos os segundos molares superiores (direito e esquerdo). Os alvéolos foram separados em dois grupos: controle (direita) preenchido com coágulo sanguíneo e experimental (esquerda) preenchido com MDDH. Os animais foram sacrificados aos 5, 10 e 21 dias. Foram realizadas análises histológicas, histomorfométricas (análise de variância - ANOVA e teste de Tukey) e imunohistoquímica para osteopontina (OPN) como indicador de osteogênese. Aos 5 dias MDDH foi incorporada pelas novas trabéculas ósseas. Aos 10 dias observou-se organização do tecido conjuntivo e trabéculas no grupo experimental. Detectou-se coloração intensa para OPN em área adjacente à MDDH no grupo experimental. Aos 21 dias no grupo experimental verificou-se trabéculas maduras. Houve diferença estatísticamente significatva (p <0,05). Maior número de trabéculas em grupos experimentais que nos grupos controle em todos os períodos de análise. MDDH implantadas em alvéolos de ratos, induz a aceleração da osteogênese. Presença OPN observada mais intensamente aos 10 dias próximo à MDDH

BACKGROUND - Despite its good capacity for regeneration, bone tissue subjected to some types of fractures or surgery that can lead to large bone defects. The major bone defects treatment strategies are based in osteoinduction or osteoconduction. Demineralized human dentin matrix (DHDM) is a biocompatible alternative to fill bone defect, improving the quantity and quality of bone produced. METHODS - Wistar rats were selected, submitted to the extraction of both second molars (right and left). Alveoli were separated into two groups: control (right) filled with blood clot and experimental (left) filled with DHDM. Animals were sacrificed at 5, 10 and 21 days. Histological and histoquantitative analyzes (analysis of variance - ANOVA, and Tukey's test) were performed and immunostaining for osteopontin (OPN) as osteogenesis indicator. RESULTS - 5 days - DHDM incorporated by new trabeculae. 10 days - connective tissue organization and new trabeculae in the experimental group. Intense staining for OPN close to DHDM in the experimental group. 21 days - experimental group showing mature trabeculae. Statistical difference observed (p<0.05). Higher number of trabeculae in experimental groups in all periods of analysis. CONCLUSIONS - DHDM implanted in alveoli induces the acceleration of osteogenesis. Presence of OPN observed more intensely at 10 days close to DHDM