leading to problems such as nerve exposure

[keannu]

1. I've asked similiar questions before, but I'm doing again to practice. Does this "leading to" refer to "which(the whole previous sentence) leads" or "and (the combination of these two conditions) leads to"? Which is the subject for "leading to"?
2.What is the difference between "wear" and "abrasion"? There seems little difference.

mo3-43 ex)One of the greatest civilizations of ancient times was the Egyptians. The ancient Egyptians excelled in many areas of science, one of these being dentistry. However, they suffered from rather unique types of dental problems due to their culture. The basic diet of Egyptians consisted mainly of plants and breads. This produced a bread which was very coarse in consistency and difficult to chew. The plants in their diet were also quite gritty as the area in which they lived was very sandy. The combination of these two conditions caused extensive wear and abrasion of their teeth, leading to problems such as nerve exposure.

[keannu]

Thanks a lot! So you mean the subject for "leading to" is "The combination of these two conditions ", not the whole previous sentence?

[Barb_D]

No, the subject for "leading" is wear and abrasion.