Microbial load after selective and complete caries removal in permanent molars: a randomized clinical trial

Abstract The aim of this randomized clinical trial was to compare the remaining microbial load after treatments based on complete and selective caries removal and sealing. Patients with active carious lesions in a permanent molar were randomly allocated into 2 groups: a test group (selective caries removal-SCR; n=18) and a control group (complete caries removal - CCR; n=18). Dentin samples were collected following the excavation and three months after sealing. Streptococcus species, Streptococcus mutans, Lactobacillus species, and total viable microorganisms were cultured to count the viable cells and frequency of species isolation. CCR resulted in significant lower total viable microorganisms counts (p≤0.001), Streptococcus species (p≤0.001) and Lactobacillus species (p≤0.001) initially. However, after sealing, a decrease in total viable microorganisms, Streptococcus species, and Lactobacillus species in the SCR resulted in no difference between the groups after 3 months. In conclusion, selective caries removal is as effective as complete caries removal in reducing dentin bacterial load 3 months after sealing.

Resumo O objetivo deste ensaio clínico randomizado foi comparar os microrganismos remanescentes após tratamentos baseados em remoção total de tecido cariado e selamento e a remoção seletiva de tecido cariado e selamento. Pacientes com lesões de cárie ativas em molares permanentes foram divididos aleatoriamente em dois grupos: grupo teste (remoção seletiva de tecido cariado-SCR; n=18), e grupo de controle (remoção total de tecido cariado-CCR; n=18). Amostras de dentina foram obtidas após a remoção da tecido cariado e após 3 meses de selamento das cavidades. Streptococcus spp., Streptococcus mutans, Lactobacillus spp. e microrganismos viáveis totais foram cultivados para contagem de células e frequência de isolamento de espécies. CCR resultou em menores contagens totais de microorganismos viáveis (p≤0,001), Streptococcus spp. (p≤0,001) e Lactobacillus spp. (p≤0,001) inicialmente. Entretanto, após o selamento, uma redução significativa nas contagens totais de microrganismos viáveis, Streptococcus spp. e Lactobacillus spp. resultou em nenhuma diferença entre os grupos após 3 meses. Conclui-se que a remoção seletiva de cárie é tão seletiva quanto a remoção completa de cárie na redução da infecção dentinária após três meses com selamento da lesão.

Morphological Assessment and Cleaning Capacity of a Reciprocating System in Root Canals of Deciduous Teeth

Objective:To assess root canal morphological results and cleaning capacity in deciduous teeth instrumented with a reciprocating system.Material and Methods:15 deciduous molars and a total of 24 canals were selected for the study. Nine teeth(13 canals) were selected at random for microbiological analysis and 6 teeth (11 canals) were used for tomographic analysis of morphology. The roots used for the microbiological assessment were contaminated with standard strains of Enterococcus faecalis. All roots were instrumented using the WaveOne System with a Small (21:06) 21mm file and an X-Smart plus motor. Tomography was conducted with an I-CAT machine before and after instrumentation with the objective of analyzing the WaveOne System's shaping capacity. Statistics: Biostat 4.0 software was used to analyze results. The microbiological results (log10) and tomographic results (pixels) were analyzed using descriptive statistics and the Wilcoxon test.Results:There was a significant reduction in Enterococcus faecalis colony-forming units after instrumentation of the root canal systems of deciduous molars using the WaveOne system (p=0.0033) and significant enlargement of the root canal systems was observed after instrumentation (p=0.047), while morphology was maintained. Conclusion:The WaveOne System, using the Small file was effective for disinfection of the root canal systems of deciduous molars

The antimicrobial effect of iodine-potassium iodide after cleaning and shaping procedures in mesial root canals of mandibular molars

The aim of this study was to evaluate the antibacterial activity of 2% iodine potassium iodide (IKI) used as a final rinse after the cleaning and shaping procedures in mesial root canals of mandibular molars infected with Enterococcus faecalis. Seventy two mandibular first molars were used. The root canals were infected with Enterococcus faecalis for 30 days. After the infection procedures, the root canals were cleaned and shaped by using the ProTaper rotary system and manual files. The teeth were randomly assigned to four experimental groups (N=18). In group 1, the root canals were irrigated with sterile distilled water (control). In group 2, the root canals were irrigated with 1% Sodium hypochlorite (NaOCl) during instrumentation. In group 3, root canals were irrigated with 1% NaOCl during instrumentation and a five minute final irrigation using 2 % IKI. In group 4, the root canals were irrigated with 1% NaOCl during instrumentation and a 15 minutes final irrigation with 2 % IKI. Bacteria colony-forming units (CFU) from root canals were semi-quantified and the presence of negative cultures among the groups was compared using Fisher’s test (p < 0,05). The order of effectiveness was: 1% NaOCl plus 2% IKI for 15 minutes (95%), 1% NaOCl plus 2% IKI for 5 minutes (44%), 1% NaOCl (17%) and sterile distilled water (0%). Fisher’s exact test showed a significant difference among the groups (p<0.05). It was concluded that under in vitro conditions, IKI was able to eliminate the Enterococcus faecalis from infected dentin significantly in a 15-minute time frame after the cleaning and shaping procedures.

El objetivo del presente trabajo fue determinar el efecto in vitro del yoduro de potasio yodado al 2% posterior a la preparacion quimiomecanica en conductos radiculares infectados con Enterococcus faecalis. Para este estudio, se emplearon 72 primeras molares inferiores permanentes de humanos, los cuales fueron infectados con Enterococcus faecalis ATCC 29212. Los conductos fueron preparados mediante instrumentacion rotatoria y distribuidos de manera aleatoria en cuatro grupos de acuerdo al irrigante empleado: Grupo 1, agua destilada esteril; Grupo 2, NaOCl al 1%; Grupo 3: NaOCl al 1% IKI al 2% durante cinco minutos; y, Grupo 4: NaOCl al 1% mas IKI al 2% durante 15 minutos. Se tomaron muestras pre y postoperatorias de los conductos y se realizo la semicuantificacion microbiologica de las unidades formadoras de colonias de las bacterias. Fue comparada la presencia de cultivos negativos en los grupos mediante el test de Fisher utilizando un nivel de significancia de p < 0.05. El orden de efectividad para la desinfeccion de los conductos radiculares de mayor a menor fue: NaOCl al 1 % mas IKI al 2% durante 15 minutos (95%), NaOCl al 1% mas IKI al 2% durante 5 minutos (44%), NaOCl al 1% (17%) y agua destilada (0%). Se concluye, que bajo las condiciones in vitro de este estudio, el yoduro de potasio yodado empleado despues de la instrumentacion fue capaz de eliminar significativamente a la bacteria Enterococcus faecalis en un tiempo de 15 minutos.

Evaluation of food retention in occlusal surfaces of first primary molars / Evaluación de la retención de alimentos en las superficies oclusales de los primeros molares temporales

Some food characteristics, like stickiness and consistency, can modify the time for food removal from the mouth as well as favors the activity of cariogenic bacteria, increasing dental caries risk. This study aimed to observe food retention in contact with a cariogenic substrate in 24-30 months old children. Therefore, 27 children (54 teeth) were evaluated. They intake a chocolate cookie and the food retention area was documented by digital photography in two experimental times (to: 0 and t1: 30 minutes) and it was calculated using Image Tool 3.0 software. The food retention surface index (mm2) was statistically reduced (Wilcoxon’s test, p=0.001) after 30 minutes for both maxillary (to: 0.37 +/- 0.04 and t1:0.042 +/- 0.015) and mandibular (to: 0.30 +/- 0.03 and t1: 0.078 +/- 0.019) molars. No differences were observed between the groups in food retention surface index at the initial time. At the final time, the mandibular molars show a higher retention area than the maxillary ones (Mann-Whitney’s test, p=0.04). The prevalence of food retention at the mandibular molars is higher than the maxillary molars (Chi Square’s test, p=0.03). In conclusion, first primary mandibular molars retain more food than the maxillary molars, being in agreement with clinical results of dental caries’ prevalence.

Algunas características de los alimentos, como la viscosidad y consistencia, puede modificar el tiempo para el retiro de alimentos de la boca, así como favorecer la actividad de las bacterias cariogénicas, y el aumento de riesgo de caries dental. Este estudio tuvo como objetivos verificar la retención de alimentos en contacto con un sustrato cariogénico en niños de 24-30 meses de edad. 27 niños (54 dientes) fueron evaluados. Se realizo la ingesta de una galleta de chocolate, y la zona de retención del alimento fue documentada por la fotografía digital en dos tiempos de experimentación (to: 0 y t1: 30 minutos) y se calculó utilizando el software Image Tool 3.0. El índice de superficie (mm2) de retención de alimentos fue estadísticamente reducido (test de Wilcoxon, p = 0,001) después de 30 minutos para molares maxilares (to: 0,37 +/- 0,04 y t1: 0,042 +/- 0,015) y mandibulares (to:0,30 +/- 0,03 y t1: 0,078 +/- 0,019). No se observaron diferencias en El índice de superficie de retención de alimentos entre los grupos en el tiempo inicial. En el momento final, los molares inferiores muestran una zona de retención superiores a los maxilares (prueba de Mann-Whitney, p = 0,04). La prevalencia de la retención de alimentos en los molares inferiores fue más alta que los molares superiores (Chi cuadrado, p = 0,03). En conclusión, los primeros molares mandibulares primarios retienen más alimentos que los molares superiores, siendo concordante con los resultados clínicos de la prevalencia de caries.

Effect of fluoride varnish on Streptococcus mutans counts in plaque of caries-free children using Dentocult SM strip mutans test: a randomized controlled triple blind study.

Dental caries is one of the most prevalent infectious diseases and although of multifactorial origin, Streptococcus mutans is considered the chief pathogen in its development. Fluoride is one of the most effective agents used for the reduction of dental caries apart from oral hygiene maintenance. AIMS: The aim of this study was to estimate the counts of Streptococcus mutans and to evaluate the effect of Fluor Protector fluoride varnish on these counts in the plaque of caries-free children using Dentocult SM Strip Mutans. MATERIALS AND METHODS: Thirty caries-free subjects were selected for the study based on the information obtained from a questionnaire and were randomly assigned to the control group consisting of ten subjects and the study group consisting of twenty subjects. Plaque samples were collected on the strips from the Dentocult SM kit and after incubation, the presence of Streptococcus mutans was evaluated using the manufacturer's chart. The study group was subjected to a Fluor Protector fluoride varnish application following which the samples were collected again after 24 hours. RESULTS: The average Streptococcus mutans counts in the primary dentition of caries-free children before and after the application of Fluor Protector fluoride varnish were 10(4)-10(5) colony forming units (CFU)/ml and <10(4) CFU/ml respectively. CONCLUSION: The results showed that the study group had a statistically significant reduction in the plaque Streptococcus mutans counts than the control group.

Estreptococos cariogénicos predominantes, niveles de infección e incidencia de caries en un grupo de escolares: estudio exploratorio / Predominant cariogenic Streptococcus, infection level and caries incidence in a group of schoolchildren: en exploratory study

Objetivo: Estudiar la distribución de estreptococos cariogénicos, niveles de infección y su asociación con la incidencia de caries. Metodología: Sesenta escolares (8 y 10 años), seguidos durante 18 meses. Se registró caries, niveles bacterianos de estreptococos en muestras de placa; por medio de análisis bioquímico se hizo la tipificación bacteriana, se calculó la incidencia de caries en el molar muestreado. Resultados: El 80 por ciento de los estreptococos correspondieron al grupo mutans (40 por ciento S. sobrinus, 32 por ciento S. mutans, 5 por ciento S. rattus y 3 por ciento S. cricetus). El 20 por ciento restante correspondió a otros estreptococos (S. salivarius, S. mitis y S. sanguis). El 55 por ciento de los niños presentó conteos 105 ufc/mL en placa y el 30 por ciento desarrolló caries en el molar estudiado. Un modelo de regresión logística múltiple de pasos sucesivos mostró asociación entre la bacteria predominante y los niveles de infección (P < 0.01). No se demostró asociación entre bacteria predominante e incidencia de caries (P > 0.05). Sin embargo con el mismo modelo ponderado según los niveles de infección, mostró una asociación significativa (P < 0.0018). Conclusión: La asociación de cepas de estreptococos con la incidencia de caries en niños es dependiente del nivel de infección

Eficacia antimicrobiana de las soluciones de hidróxido de calcio y clorhexidina al 0.1 por ciento sobre la flora bacteriana de molares temporales necrosados / Antomicrobial efficacy of calcium hydroxide and chlorhexidine solutions of 0.1 percent to the bacterial flora of necrosed temporal tooth

En el presente trabajo se realizó un estudio comparativo de la eficacia antimicrobiana in vitro de las soluciones de hidróxido de calcio y clorhexidina al 0.1 por ciento sobre la flora bacteriana aislada de molares temporales necrosados de niños entre cinco y ocho años. Las muestras fueron sembradas en placas petri con agar sangre heminamenadiona. A una de las placas se le colocó en la superficie un disco de papel filtro embebido en clorhexidina al 0.1 por ciento, a otra placa hidróxido de calcio y la tercera fue usada como control. En estas condiciones fueron cultivadas en anaerobiosis por siete días. Se concluyó que el efecto antibacteriano in vitro de la clorhexidina es significativamente mayor que el del hidróxido de calcio sobre la flora bacteriana aislada de molares temporales necrosados