Analysis of enterococcus faecalis, staphylococcus aureus, and candida albicans in cast metal cores / Análisis de enterococcus faecalis, staphylococcus aureus y candida albicans en núcleos colados en metal base

ABSTRACT. Introduction: all dental treatments should strictly follow aseptic protocols in order to reduce failure, especially when performing endodontic procedures. Despite being a key recommendation in this type of interventions, this statement is generally ignored, as students and clinicians tend to neglect the sterilization of posts prior to their use. To raise awareness on this practice, the objective of this study was to demonstrate the presence of microorganisms that cause failure, such as Enterococcus faecalis, Staphylococcus aureus and Candida albicans, in non-sterile cores. Methods: during the first half of 2016, fabricated cast cores were collected in the dental clinics of Universidad Cooperativa de Colombia at Villavicencio. The cores were immersed in saline solution making dilutions to up to 10-4, and finally inserted in duplicate into differential mediums for the microorganisms under study. The candidate colonies were then quantified and selected for the microorganisms under study, performing identification and confirmation in a certified clinical laboratory. Results: the presence of E. faecalis was detected in one of the cores (3.2%) used in the clinic, quantified in 5x104 CFU/ml. The presence of S. aureus or C. albicans was not identified, but other microorganisms were found, such as Candida parapsilopsis (35.5%), Candida tropicalis (6.5%), Kokuria kristinae (16.1%), Staphylococcus saprophyticus (12.9%) and Stenotrophomona maltophilia (3.2%). Conclusion: out of the microorganisms analyzed in this study, only E. faecalis was identified. However, other microorganisms associated with endodontic failure or other type of complications were identified.

RESUMEN. Introducción: el tratamiento odontológico debe considerar rigurosamente la cadena de asepsia para reducir el fracaso, incluso cuando se realizan procedimientos endodónticos. A pesar de ser una recomendación clave en este tipo de intervenciones, esta afirmación no tiene el suficiente alcance, debido a que algunos estudiantes y profesionales no consideran la esterilización de los núcleos antes de utilizarlos. Para generar conciencia en torno a esta práctica, el objetivo de este estudio consistió en demostrar la presencia de microorganismos desencadenantes del fracaso, como Enterococcus faecalis, Staphylococcus aureus y Candida albicans, en los núcleos sin esterilizar. Métodos: de las clínicas odontológicas de la Universidad Cooperativa de Colombia, sede Villavicencio, se recolectaron núcleos colados fabricados durante el primer semestre de 2016. Los núcleos fueron colocados en solución salina y se realizaron diluciones hasta 10-4, para finalmente sembrarlas por duplicado en medios diferenciales para los microorganismos objeto de estudio. Posteriormente se cuantificaron y seleccionaron las colonias candidatas para los microorganismos estudiados y se realizó la identificación y confirmación en un laboratorio clínico certificado. Resultados: en uno de los núcleos utilizados en la clínica se detectó la presencia de E. faecalis (3,2%), cuantificado en 5x104 UFC/ml. No se identificó la presencia de S. aureus ni C. albicans, pero se encontraron otros microorganismos, como Candida parapsilopsis (35,5%), Candida tropicalis (6,5%), Kokuria kristinae (16,1%), Staphylococcus saprophyticus (12,9%) y Stenotrophomona maltophilia (3,2%). Conclusión: de los microorganismos analizados en este estudio, solo se identificó la presencia de E. faecalis. Sin embargo, se identificaron otros microorganismos asociados al fracaso endodóntico o a otro tipo de complicaciones.

A STUDY OF CORE TYPE AND LUTING CEMENTS ON COMPLETE CAST CROWN RETENTION / 대한치과보철학회지

The purpose of this study was to compare the retention of complete cast crown over amalgam cores, composite resin cores, and cast gold cores when cemented with three different luting agents. Eighteen core specimens each of amalgam(Bestaloy, Dong Myung, Seoul, Korea), composite resin (Z100, 3M Dental product, st. Paul, Minn) and type N gold alloy (Ba 4, Heesung Engelhard Corp., Korea) were made in a customized milling stainless steel die. A wax pattern with a loop attached to occlusal surface was made for each core and a type 11 gold alloy casting was fabricated. The castings which had clinically acceptable marginal fit were used as test samples. The following luting cements were used to cement cast crowns on each core material : (1) zinc phosphate cement (Confi dental Products Co., USA) (2) glass-ionomer cement (Fuji Plus, GC Industrial Corp., Tokyo, Japan) (3) resin cement (Panavia 21, Kuraray Co., USA). All cements were mixed according to manufacturers instructions. A static load of 5kg was then applied for 10 minutes on the crowns. All specimens were stored in saline solution for 24 hours at 371C and thermocycled for 500 cycles. After storage and cycling, the tensile bond strengths were measured by using a universal testing machine (Instron Corp., Canton, Mass.) at a crosshead speed of 0.5mm/min. The results were as follows : 1. The retentive strength of resin cement was the highest of all three types of cement for resin core (p0.05). 3. The retentive strength of resin cement was higher than that of zinc phosphate for cast core, but there was no difference between the retentive strength of glass ionomer cement and those of rein and zinc phosphate cement. 4. The retentive strength of the zinc phosphate cement for amalgam core was the highest of all type of cores.