The research project is aimed at “growing” bone in the area where a tooth was lost so that a dental implant can be inserted there.

The bone is supposed to grow into a porous three-dimensional (3D) scaffold for preserving the ridge’s height and width after a tooth is extracted.

The patented scaffold was jointly developed by National Dental Centre Singapore (NDCS ) and Nanyang Technology University (NTU). It looks like a small white mesh, and is made of a bioresorbable synthetic polymer, which is absorbed by the body.

It was inspired by a similar scaffold used in neurosurgery to plug burr holes drilled in the skull to release excess fluid in the brain, said Clinical Associate Professor Goh Bee Tin, Principal Investigator, Deputy Director, Research and Education, and Senior Consultant, Department of Oral & Maxillofacial Surgery, NDCS.

Prof Goh raised the possibility of using it for dental implants with the scaffold’s inventor, NTU’s Professor Teoh Swee Hin, Chair, School of Chemical and Biomedical Engineering. Prof Goh also provided specifications for its manufacture.

A pilot trial run with seven patients showed that the scaffold reduced vertical shrinkage of the bone surrounding an extracted tooth. A randomised controlled trial with 138 patients is now being conducted, but for this trial, a new polymer, which encourages even more bone growth, is being used.

Prof Goh said that if the trial is successful, the scaffold could become an established procedure for preserving bone before dental implants, saving many from painful and costly bone grafts, and reducing treatment time.

How it is done

She said dental implants – because of their predictable success – are now very popular with patients who want them instead of dentures. An estimated 15,000 are done each year in Singapore.

However, if extracted teeth have been missing for some time, the bone in the
jaw would have shrunk from disuse, and patients would need bone grafting first.

Bone is taken most commonly from the jaw, but if this is not enough, it will be taken from the hip or leg. The bone is attached to the tooth socket with tiny screws. Healing takes around six months, and then the dental implant is inserted.

Prof Goh said a dental implant can be done immediately after a tooth is pulled out if there is sufficient bone in the jaw. But when this is not possible, the area is left for two to three months to allow the bone to heal before inserting a dental implant.

Traditionally, to reduce bone shrinkage during this healing period, the tooth socket is packed with a bone substitute, usually from cows. But being foreign body, it is not the same as live bone, which is needed to ensure the success of the implant over time.

By contrast, the scaffold is porous and lets blood through, encouraging bone to grow into the structure. It is shaped with a surgical blade to fit snugly into the tooth socket. The gums are then stitched over.

Its 3D shape helps maintain the contour of the ridge. The dental implant is put in six months later, capped by a crown.

The researchers are now looking into how else to use the scaffold.

“We are talking about using it for growing bone for other applications, such as whole segments of the jaw, but that would be more challenging.”
Professor Goh Bee Tin, Principal Investigator, Deputy Director, 
Research and Education, and Senior Consultant, 
Department of Oral & Maxillofacial Surgery, NDCS.

This would help patients who have parts of their jaw removed due to tumours.

This story was first published in Singapore Health, Jan-Feb 2018 issue.