Biologic monitoring of dental office sterilizers in Mexico.

BACKGROUND: Biologic indicators (BIs) are the quality control applicable to sterilization cycles, but their use was not previously taught in Mexican dental schools or recommended by professional associations. A Mexican official standard, the Mexican Official Norm, published by health authorities in 1999 makes it compulsory for dentists to biologically verify sterilization cycles. However, only a few dentists comply because the use of BIs is largely unknown and the standard is not being enforced. OBJECTIVE: To evaluate the incidence of sterilization failures in a convenience sample of dental offices in Mexico. METHODS: Spore strips were distributed to dentists interested in using this service. The dentists mailed the processed BIs to the laboratory for culture. RESULTS: In 6 years, 3277 tests were submitted from 82 dental offices. Thirty-four offices (41%) submitted 1 to 12 tests, 22 (27%) sent 14 to 48 tests, 18 (22%) mailed 49 to 96 tests, and 8 (10%) sent >97 tests. The sterilization methods were steam (74.4%), dry heat (20%), and chemical vapor (5.6%). A total of 242 sterilization failures (7.4% of all cycles) were detected. Convection dry heat failed with a greater frequency with chi(2) analysis (chi(2) = 13.71, P =.0175). CONCLUSIONS: Sterilization failures occurred in instrument loads used in patient treatment. Steam and chemical vapor under pressure failed less often than convection dry heat. When corrective action is taken, routine use of BIs increases patient safety.

El cloruro de benzalconio: inaceptable para esterilizar o desinfectar instrumental médico dental / Benzalkonium chloride is unacceptable to sterilize o disinfect medical or dental instruments

Objetivo. Comparar la actividad esporicida del cloruro de benzalconio (CB) con la del glutaraldehído. Material y métodos. Estudio comparativo, hecho en el Laboratorio de Microbiología de la Facultad de Odontología, Universidad Nacional Autónoma de México (UNAM). Se expusieron esporas de Bacillus subtilis ATCC 9372 a estos germicidas (1 espora x µl) sobre un filtro de 0.22 µm. Al completarse el tiempo de contacto, se lavaron las esporas y los filtros fueron incubados sobre agar nutritivo por 72 h a 37§C. Resultados. El CB no eliminó las esporas de B. subtilis a la concentración de uso, ni aun al incrementar a 15 h su exposición (900 veces el tiempo recomendado). El glutaraldehído al 2 por ciento destruyó las esporas después de 10 h. La urea y el cloruro de sodio no mostraron actividad esporicida. Conclusiones. Los resultados confirman que el CB carece de actividad esporicida y ratifican que este compuesto cuaternario de amonio no tiene aplicación como agente esterilizante o como desinfectante de instrumental médico y dental. El texto completo en inglés de este artículo está disponible en: http://www.insp.mx/salud/index.html