No, you cannot use a 100w bulb instead of a 55w bulb. The reason for this is because the wattage output of a light bulb determines the amount of light that is produced. Therefore, if you were to use a 100w bulb in place of a 55w bulb, the100w bulb would produce more light than the 55w bulb. This could potentially create problems such as over-illumination or glare.