Should I be worried about the gaps between my teeth caused by molar bands?

There are very few situations where there is no need to remove some bulk from the tooth to fit veneers. You have large gaps in between your teeth. Your teeth are already thinned down from previous fillings or acid erosion (you must still have enamel covering the tooth surface for predictable long-term bonding). If BOTH of these criteria exist, then it may be possible to have porcelain veneers without much trimming. Trimming tooth structure for veneers achieves 2 functions: Creates an end-stop for the porcelain to end and to allow easier seating of the veneer.

MTA (Mineral Trioxide Aggregate) is a good choice for sealing the root canal especially in cases where there is an open root apex or a perforation. An open root apex occurs when the normal root development is either incomplete (as in an immature permanent tooth) or interrupted (when the nerve or pulp dies in an immature permanent tooth). The normal sequence of root development causes thickening of the dentinal walls and resultant shrinkage of the size of the apical root canal opening (also known as the apical foramen).