Overview

 

Bone grafting is the replacement or augmentation of the bone around the teeth. Bone grafting is a surgical procedure that places new bone or a replacement material into spaces between or around broken bone (fractures) or in holes in bone (defects) to aid in healing.

How does a bone braft material form bone?

 

Bone grafting is used in any of the following three ways to repair a bone defect.

  • Osteogenesis – is a process in which new bone is formed by the cells that are contained in the graft
  • Osteoinduction – is a chemical process wherein the graft molecules (BMP) convert the patient's cells into cells that are capable of forming bone.
  • Osteoconduction – is the provision of a scaffold for the growth of new bone

Why is bone grafting necessary?

 

Bone loss or destruction occurs due to periodontal disease or trauma. In such cases bone grafting is performed to regenerate the lost bone.

The following are some of the reasons why bone grafting is required:

  • Dental Implants – if a Dental Implant is to be successful it is necessary that the patient has adequate bone in the jaw for placing the implant. The bone healing after the removal of the tooth is dependent on the bone quality and quantity. In the earlier days it was believed that if the patient does not have sufficient jaw bone he won’t be suitable for dental implants. Since then situation has changed because of the technological advances and bone grafting helps in bone augmenting.
  • Removable prostheses – needs bone augmentation. Bone grafts are also used to augment bone to enhance the fit and comfort of removable prostheses, or to enhance esthetics of a missing tooth site in the smile zone. When one loses a tooth, as in an extraction, the surrounding bone collapses. To preserve this bone for future implant placement or for esthetics, a bone graft is used.

What are the types of bone grafts?

 
  • Autografts – in this type of grafting bone is taken from one area of the patient’s body and transplanted to another area that requires grafting; this has been very successful. Normally the bone is harvested either from the hip or from the mouth of the patient and this is grafted onto the patient’s jawbone. The compatibility of the jaw bone of the patient with the harvested bone from patient’s body is high and this makes this technique most successful.
  • Allograft – in this type of grafting the bone used is from a bone bank – cadaver bone that has been created from human bone donors. Bone harvested in this manner goes through various sterilization techniques to ensure that it is safe as a graft. This donor bone will be finally converted as natural bone while building the jaw bone.
  • Xenograft – in this bone is harvested from animals such as cows and this bone is processed to ensure sterility and biocompatibility. Animal bone acts as filler initially and the patient’s body will replace this with natural bone finally.
  • Alloplastic grafts – are inert synthetic materials – a type of calcium phosphate – made by man; these grafts can be replaced with natural bone over time because many of them get resorbed into the body thereby encouraging bone growth.There are some which do not get resorbed by the body and these act as a scaffold for building natural bone.

What are the advantages and disadvantages of various types of bone grafts?

 

The advantages and disadvantages of various types of Bone grafting are tabulated below.

No Type of Graft Advantages Disadvantages
No Type of Graft Advantages Disadvantages
1 Autograft
  • The donor here is the patient himself and hence there is no possibility of disease being.
  • The probability of rejection of the bone graft by the body is negligible.
  • Since the bone is harvested from the patient it encourages new bone growth
  • This technique calls for two operations – bone harvesting and bone grafting. This increases both time and cost of operation.
  • Considerable pain will exist at the harvested site and this can last for a longer period. It can also be infected.
  • This procedure is not being performed by all dentists.
2 Xenograft
  • Since bone harvesting is not done on the patient only one surgical procedure is required
  • Natural bone growth is encouraged
  • Since all organic components of the bone are extracted there is a minimal risk of BSE or mad cow disease
  • People are reluctant to go in for this because it uses animal bone.
3 Allograft
  • Since bone harvesting is not done on the patient only one surgical procedure is required.
  • Natural bone growth is encouraged
  • Since the bone is harvested from various donors there could be bone variability.
  • There is every possibility of having immunogenic reactions
  • Risk of disease transfer
  • Slow integration of donor bone with the natural bone
  • Donor bone can weaken it by 50%
  • People are reluctant to go in for this because it is a donor bone.
4 Alloplastic grafts
  • Since bone harvesting is not done on the patient only one surgical procedure is required.
  • No possibility of disease transfer
  • The dentist can procure exact quantity of synthetic bone for successful grafting.
  • Manufactured in various sizes and shapes thereby facilitating a perfect fi
  • Manufactured from biodegradable material and hence safer to be used in the body
  • Weakening of the graft during the procedure
  • Likely to be rejected by the body at times

What is the procedure followed for bone grafting?

 

The dentist will incise the gum at the bone defect site and reflect a flap. He will then place the bone to be grafted onto the exposed jaw bone. Then he will replace the flap of the gum and stitch it back into the place. The time of healing will vary from person to person and on the average time takes about 6 months. Patients are administered a course of antibiotics after placing the bone graft. The dentist might also prescribe antiseptic mouthwashes to preserve the gum that covers the bone graft.