Análisis con microscopía electrónica de la durabilidad de cuatro marcas comerciales de fresas de diamante al desgastar dientes naturales

Background: Using elements with appropriate state and cut, is the method of choice to ensure the surface doesn’t lose the initial moisture and avoid later injuries, or pulp overheating, if a blunt or worndown tool is used. Little information is available about wear efficiency of diamond coated burs, that also relates the amount and quality of diamonds on the surface of the rotary instrument, according to the number of uses, and the deleterious effects of the diamond coated burs upon the pulp, and the influence over the dentinal sensitivity of the patient. Aim: To evaluate the durability of cut diamonds on the active surface of the high speed diamond coated burs, after making a number of wears on natural teeth, thus providing a margin of use of diamond coated burs. Methods: An ex vivo study comparing four commercial brands of rotary diamond instruments grain within the range (64 -126 microns) tapered round toe type (ISO 850) was conducted: MDT® (ISRAEL), SWISSTECH® (COLTENE-SWITZERLAND), POINTECH® (CHINA), JOTA® (SWITZERLAND), after 5 clinical applications in dental enamel. Five cuts were made in enamel tooth crown. Subsequently, rotary instruments took scanning electron microscopy to observe: a) diamond substrate adhesion in the head and body, b) state of the diamond substrate in the head and body, after 5 cuts in enamel c) final state of the diamond rotary instrument used. Results: A qualitative and quantitative analysis was performed. The four brands tested were unchanged after 5 applications made to enamel, so that both the head and body had the same wear. Although all samples showed variations in some representative was most evident, the eviction and breaking of diamonds. Conclusion: It´s necessary to change the rotary diamond instruments, after 5 uses, to have a good coated tissue and to avoid pulp damage, or restorative materials adhesion failure.