The most common side effect in tooth bleaching is tooth sensitivity because of the pulp reaction to free radicals produced by the hydrogen peroxide used in bleaching products. Different therapies have been used before, during and after to reduce tooth sensitivity, agents that block nerve repolarization such as potassium nitrate and agents that block dentinal tubules: amorphous calcium phosphate, calcium sodium phosilicate, calcium gluconate, hydroxyapatite, GLUMA and fluor; alternative therapies such as the use of anti-inflammatory, antioxidants and laser application which have also been mentioned in the literature. The aim of this review is to show the scientific evidence on the different methods to decrease the sensitivity on tooth bleaching.

Objetivo: Evaluar la degradación de fuerzas de las cadenas elastoméricas American Orthodontic® expuestas a bebidas carbonatadas: Coca Cola®, Inca Kola® y Kola Real® en seis intervalos de tiempo: 0 (inicial), 1 día, 7 días, 14 días, 21 días y 28 días. Materiales y Métodos: Se emplearon 48 segmentos de cadena elastomérica (American Orthodontic®, Sheboygan, USA) que fueron divididas en cuatro grupos (n= 12): Tres grupos fueron expuestos a cada bebida carbonatada (Cola Cola®, Inka Cola® y Kola Real®) y agua destilada (control) en dos ciclos de 15 minutos dos veces diarias durante 28 días. Las fuerzas (gf) fueron medidas con una máquina de ensayo universal (Zwick, Ulm, Alemania) en seis intervalos de tiempo (inicial, 1 día, 7 días, 14 días, 21 días, y 28 días). Resultados: Existe diferencia estadísticamente significativa en la degradación de las fuerzas entre las beb...

   Objective: To evaluate the resistance to cyclic fatigue of a replica rotary system in comparison with its original system. Method: F2 rotary instruments (n=19 per group) from the original brand ProTaper Gold system (Dentsply Maillefer, Ballaigues, Switzerland) were compared with a Super File III instrument (n=19 per group) from a Denco replica system (Medical Co., Shenzhen, China) regarding cyclic fatigue strength. The instruments were randomly distributed into two groups, according to the file brand. Subsequently, the fatigue cycle was measured; for which, they were activated using the E-mate Pro motor of the Denco brand (Medical Co., Shenzhen, China) at continuous rotation 300 rpm and a torque of 2.5 Ncm. Results: The fracture resistance time was recorded and statistically compared between both groups according to the type of instrument (original system/replica system) using the ...