You are right. You need orthodontic treatment. Composite resin is another ideal material when restoring diastema closures.
But cost of the treatment and consultation charges depends on orthodontist you choose. You might also need cleaning, polishing, and bleaching for your teeth since you have yellow teeth.
Next Steps
Visit orthodontist and aesthetic restorative dentist to discuss more about it.
Health Tips
The decision to approach treatment orthodontically or restoratively is one that must be shared among the patient, orthodontist, and aesthetic restorative dentist.