You can fill the gap with cosmetic filling but depends on your tooth size. They should look proportionate post filling Also you have an option of braces . Metal or clear braces for which the treatment would be around 6 months or you could try Invisalign or other clear ALIGNERS for which the treatment would be around 3 month

1st point to consider is whether you have had the gap since the time the teeth erupted, or has it developed /increased over the years. In the first case, you can opt for braces (traditional /invisible) or any cosmetic procedure permissible within the Golden proportion of your teeth. In the second scenario, the causative factor/s need to be identified and treated before closing the gap.

There are 3 ways to get your smile corrected. 1)Add cosmetic fillings to fill the gap keeping the golden proportion of your teeth and smile in mind. 2)go for orthodontic treatment commonly known as braces, and align your teeth filling the gaps maintaining the naturalness of your teeth 3)u can choose for laminates and bond them to your teeth giving you a idel smile line. Choosing any of these 3 options is the patients choice. It depends upon the your budget, preference, and the time period of your treatment you will to undergo