Candice McMullan-vogel D.D.S., Dr. med. dent.
Current evidence does not clearly indicate which bone augmentation procedures may be most effective or whether such bone is of benefit to the patient.
A more critical approach is required when evaluating the need for bone augmentation and determining which procedure might be most beneficial to the patient.
Is bone augmentation necessary for implant therapy? Which is the most effective technique for specific clinical indications?
The authors included randomized controlled clinical trials (RCTs) involving patients in whom alveolar bone augmentation may be indicated before or during dental implant placement. Outcome measures included prosthesis, implant or augmentation procedure failure, major complications at the treated/augmented and/or bone donor sites, bone gain and patient satisfaction. The authors conducted an all-language search of several databases (through January 2008) and relevant dental journals. To locate unpublished or ongoing RCTs, the authors contacted selected authors and dental implant manufacturers. Two review authors independently duplicated the selection of studies for inclusion, evaluated their study quality, and performed data extraction.
The authors identified 17 RCTs (reporting the outcome of 455 patients), out of potentially 40 RCTs, suitable for inclusion. Ten trials evaluated different techniques for major bone augmentation procedures (vertical and/or horizontal bone augmentation), 4 trials evaluated different techniques of bone augmentation for implants placed in extraction sockets, and 3 trials evaluated different techniques to treat bone dehiscence/fenestration around implants. Eleven studies were judged by the authors to have a high risk of bias, 6 to have a low risk. Because different techniques were studied, meta-analysis could not be performed. Few statistically significant differences were found between study groups.
Current evidence does not indicate which bone augmentation procedures may be most effective or whether such bone is of benefit to the patient. While various techniques can be used to augment bone horizontally and vertically, it is unclear which one is the most effective technique. Major bone grafting procedures of resorbed mandibles may not be justified. Bone substitute (Bio-Oss (bovine bone) or Cerasorb (beta-tricalcium phosphate)) may be used to replace autogenous bone, even for sinus lift procedures. The use of particulate autogenous bone from intra-oral locations, may be associated with an increased risk of infection.
Source of Funding:
School of Dentistry, The University of Manchester, UK; The Health Foundation, UK; Swedish Medical Research Council, Sweden.
Importance and Context:
In some patients bone augmentation may allow dental implant placement. There are numerous techniques and materials currently used to augment bone. New techniques and materials are continuously introduced and some treatment options have strong proponents claiming a particular material or technique offers improved success. It is possible that many procedures are performed despite the lack of documented clinical benefit to the patient. The paradigm that autogenous bone is the gold standard for bone augmentation procedures was not confirmed in this review and the majority of the trials suggested that this may not be the case. The use of autogenous bone appears to be associated with an increased risk of complications. Bone substitutes might be able to replace autogenous bone.
Strengths and Weaknesses of the Systematic Review:
The authors used thorough, well-defined, and clinically relevant methods to search, evaluate and present the evidence. However, the scope of this review was very broad with the authors addressing several questions. Only 17 RCTs, with small study sizes, were judged suitable for review. Although the review authors list several conclusions, each was based on very few studies with qualifiers for each concluding statement. The review authors provide limited but useful clinical information which should be carefully evaluated by clinicians when deciding whether to preform a bone augmentation procedure.
Strengths and Weaknesses of the Evidence:
The evidence was limited due to the few RCTs, all with small study sizes, which likely made them underpowered to detect any significant differences in outcome measures between the groups. Additionally, the authors were unable to combine information for meta-analyses because different procedures and materials were evaluated, which greatly limited the available body of evidence upon which they based their conclusions.
Implications for Dental Practice:
Reliable evidence is lacking to indicate whether bone augmentation is effective and which procedures may be most effective for specific clinical situations. This review did not confirm the paradigm that autogenous bone is the gold standard for bone augmentation procedures. In fact, the majority of the trials suggested this may not be the case. A more critical approach is suggested when evaluating the need for bone augmentation for implant therapy and caution is recommended when deciding to use any augmentation procedure.