1-If your teeth are healthy, (no decay, cavity or leaking fillings) the best way to close spaces and gaps for front teeth is Orthodontics, and possibly invialign, Orthodontics can take time anywhere from 6 months plus up to 24 months.This method of dental treatment is advisable if you do not want any drilling done to your healthy teeth.The cost for orthodontic treatment is moderate.
2-If there are fillings or you do not like the shape or color of the teeth where the gaps exists, then porcelain veneer can take care of the shape, color, close the gap, and is strong. the cost is expensive, you will achieve your desired result within a week.
3-If you wanted the most economical and fastest way, to close the gap, then your choice will be dental bonding, in which there will be minimal or no preparation (drilling) of your teeth required, in most cases very minimal drilling, you will attain the result the same day, due to porosity of dental bonding you might get some staining but it is easy to remove when the time comes. The strength of dental bonding is not as strong as dental veneer or porcelain veneer, but if done correctly lasts a long time.
Before closing the gap for the front teeth, the occlusion and bite must be analyzed.