Ricardo Alvarez, DDS

Based on your pictures there is a noticeable overbite, if you would like to have your front teeth remove and have implants placed for cosmetic purposes this is not the best way to go, because preserving your natural teeth in healthy conditions for as long as you can is always the best option. I your front teeth are damage in a way is no longer possible to preserve them your best option is implants unfortunately once the implants are fully healed and is time to do the crowns, the anatomy of this crowns (size and shape) cannot be changed to much, because the technicians need to work on the given spaces of the patients mouth, if the shape of your crowns are shorter and thinner there will possibly be gaps in between your teeth and also with the bottom teeth. I strongly suggest a consultation with an orthodontist and an implantologist preferably under the same roof to work on full comprehensive dental treatment plan. 

Based on the described situation, the provided images and the area in wish you require the dental implant my suggestion is to do the bone graft, the implant, temporary abutment/crown and make two vertical incisions in the in the gums in the are of laterals to detached part of the gum from the bone and contour the whole front of your smile including the temporary of the implant.

By doing this technique in 90% of the patients tissue graft is not needed and the aesthetic results are better, plus the number of interventions are less. 

The symptoms you describe are those of a tooth with a fracture, a fractured tooth does not always mean having to extract the tooth, this decision mainly depends on the level of the fracture if above gum level very likely your tooth can be preserved in mouth, but if below gum/bone level the probability of preserving the tooth is lower, this can be diagnose with an x-ray or sometimes with a CT scan.

Having to cut a previous crown to remove it, re-prepare the tooth and take new impressions on a tooth that has not been previously treated with a root canal causes stress to the nerve underneath the dentine, putting the tooth is risk of needing a root canal, the possibility of this happening is very low but is always a possibility. 

The color is slightly lighter according to the provided images and the crown´s length is not even on the gum line both of this characteristics can be improved you should definitely mention it to your doctor, if the crown is sealing correctly the nonconformities that you mention don’t have much to do with the impressions.

The color can be changed with porcelain makeup and the level on the gum with tissue graft or simulating with pink porcelain just to mention some options. 

Discuss this with your doctor if not fully convince you can always redo the treatment somewhere else.