When a tooth has been taken out, the bone around the tooth socket shrinks. Artificial teeth can be used to replace missing teeth following extractions. However, loss of bone width and depth after tooth extraction can affect how successful the implant will be. This is especially the case when artificial teeth (crowns or bridges) need to be held in place by dental implants inserted into the bone of the jaw where the original teeth used to be. If the bone has shrunk too much following the loss of teeth, it makes it difficult or impossible to put dental implants into the jaw. This in turn leads to gum shrinkage. A procedure known as socket preservation (ARP) may limit the shrinkage of bone following tooth loss although there is a need for evidence of its effectiveness. Several techniques and bone substitute materials can be used to fill the socket after tooth extraction. The socket may then be covered by gums or an artificial membrane and left to heal for several months. The aim is that the bone of the old tooth socket will have kept its shape and size allowing dental implants to be inserted to support crowns or bridges so that the patient’s appearance is improved and they can eat, talk and socialise with confidence. It is also hoped that the rate of failure of dental implants will be improved.
What was the research?
A systematic review of the evidence to find out the effectiveness of various materials and techniques for keeping enough bone in the jaw (alveolar ridge preservation) after teeth have been taken out (tooth extraction). These techniques are compared to tooth extraction alone or other methods of preserving the bone, or both, in patients that need dental implants after the tooth socket has healed.
Who conducted the research?
The research was conducted by a team led by Momen A Atieh, on behalf of the Cochrane Oral Health Group. Nabeel HM Alsabeeha, Alan GT Payne, Warwick Duncan, Clovis M Faggion and Marco Esposito were also on the team.
What evidence was included in the review?
Data was extracted from 8 randomised controlled trials. A total of 233 extraction sites (teeth taken out) in 184 participants were included. Participants were adults aged 18 years or older, in good general health, needing one or more permanent teeth to be taken out and the consideration of the use of ARP (Alveolar Ridge Preservation Techniques) with the possibility of using dental implants at a later date. The review looked at the effects of four techniques and materials used for preserving the tooth extraction socket. Three studies compared socket preservation to tooth extraction alone, while five studies compared two or more different materials.
What did the evidence say?
There is limited evidence that socket preservation (ARP) can reduce bone loss compared to tooth extraction alone to allow for dental implant placement. There is no evidence that socket preservation makes any important differences to the look or lasting quality of crowns or bridges. There is no convincing evidence of any significant difference between different materials and barriers used for socket preservation.
How good was the evidence?
The quality of the evidence is judged as low due to high risk of bias of the majority of the included studies. Some evidence of reporting bias is suspected, as only two of the included trials did not receive any industry support. Further long term randomised controlled trials that follow CONSORT guidelines are required.
What are the implications for dentists and the general public?
ARP techniques can minimise the loss of ridge height and width under ideal conditions in non-molar four-wall sockets, following extraction. However, clinicians should interpret the findings of this review with caution as the quality of evidence remains low with the majority of the studies judged to be at high risk of bias.
What should researchers look at in the future?
There is a need to conduct further long-term well-designed RCTs, following the CONSORT guidelines that not only report changes in ridge height and width, but also the achieved aesthetic/prosthodontic outcomes, the need for any additional augmentation, patient outcomes, and the long-term success rates of implants placed in preserved sites. The analyses of cost-effectiveness and cost-benefit of ARP techniques are needed to compare the benefits of ARP and the cost of different grafting materials. As ARP is a relatively new intervention in dental care and the implementation of such procedure generates additional cost, an essential question to be answered resides mainly in the analysis of whether ARP can achieve tangible improvements of the clinical outcomes for the extra financial liability.
Atieh MA, Alsabeeha NHM, Payne AGT, Duncan W, Faggion CM, Esposito M. Interventions for replacing missing teeth: alveolar ridge preservation techniques for dental implant site development. Cochrane Database of Systematic Reviews 2015, Issue 5. Art. No.: CD010176. DOI: 10.1002/14651858.CD010176.pub2.