There are four types of bone in the human face and the length
of treatment for placing and restoring implants with a
"tooth" and crown depends on which type of bone the
implant is placed in. Implants have to integrate with the
surrounding bone before a tooth and crown is placed on it.
Type I bone is
comparable to oak wood, which is very hard and dense. This type
of bone has less blood supply than all of the rest of the types
of bone. The blood supply is required for the bone to harden or
calcify the bone next to the implant. Therefore, it takes
approximately 5 months
for this type to integrate with an implant as opposed to 4
months for type II bone.
Type II bone is
comparable to pine wood, which isn't as hard as type I. This
type of bone usually takes 4 months to integrate with an
Type III bone is
like balsa wood, which isn't as dense as type II. Since the
density isn't as great as type II, it takes more time to
"fill in" and integrate with an implant. 6 months time
is suggested before loading an implant placed in this type of
bone. Extended gradual loading of the implant can, however,
improve the bone density.
Type IV bone is
comparable to styrofoam, which is the least dense of all of the
bone types. This type takes the longest length of time to
integrate with the implant after placement, which is usually 8
months. Additional implants should be placed to improve
implant/bone loading distribution. Incremental loading of the
implants over time will improve bone density. Bone grafting or
augmentation of bone are often required. Bone expansion and or
bone manipulation can improve initial implant fixation.