Are there any other safe ways to close gaps without braces or invisalign?

Cosmetic dentistry: It's also possible to fix gaps cosmetically through the use of dental bonding or dental veneers, such as Lumineers.

Yes: There are braces that go behind the teeth, and removable appliances similar to retainers that can be used to close space. Also teeth can be reshaped restoratively (bonding, veneers, caps) to widen the teeth. Best advice have your General Dentist work with an Orthodontist. You'll really like the result.

Yes: one method we use are custom aligners-- they are 'like' invisalign, but cost a great deal less.

Depends on Gap: The answer will depend on the size of the gap/gaps between your teeth. Cosmetic treatments (bonding and or veneers) can close gaps quickly, but these treatments make your teeth wider, not physically closing the gaps. Orthodontic treatment physically moves the teeth together, but takes longer w/o changing the tooth structure.