Utilisation de concentrés plaquettaires autologues dans la reconstruction pré-implantaire des maxillaires

Interventions for replacing missing teeth: augmentation procedures of the maxillary sinus

BACKGROUND

Insufficient bone volume is a common problem encountered in the rehabilitation of the edentulous posterior maxillae with implant-supported prostheses. Bone volume is limited by the presence of the maxillary sinus together with loss of alveolar bone height. Sinus lift procedures increase bone volume by augmenting the sinus cavity with autogenous bone or commercially available biomaterials, or both. This is an update of a Cochrane review first published in 2010.

OBJECTIVES

To assess the beneficial or harmful effects of bone augmentation compared to no augmentation when undertaking a sinus lift procedure. Secondly, to compare the benefits and harms of different maxillary sinus lift techniques for dental implant rehabilitation.

SEARCH METHODS

We searched the Cochrane Oral Health Group's Trials Register (to 17 January 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 12), MEDLINE via OVID (1946 to 17 January 2014) and EMBASE via OVID (1980 to 17 January 2014). There were no language or date restrictions on the searches of the electronic databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of different techniques and materials for augmenting the maxillary sinus for rehabilitation with dental implants that report the outcome of implant success or failure at least to four months after initial loading.

DATA COLLECTION AND ANALYSIS

Screening of eligible studies, assessment of the risk of bias of the trials, and data extraction were conducted independently and in duplicate. Authors were contacted for any missing information. Results were expressed using fixed-effect models as there were either less than four studies or we used Peto odds ratios (ORs) for dichotomous data when there were zero cells in either the treatment or control or both arms and the number of trials was small. The statistical unit of the analysis was the patient.

MAIN RESULTS

Eighteen RCTs out of 64 potentially eligible study reports met the inclusion criteria. They compared undertaking a sinus lift with not doing so, and the use of different sinus lift techniques. There were 650 patients providing data for the outcomes evaluated. Five studies were assessed as low risk of bias, 11 were assessed as high risk of bias, and in two the risk was unclear. Sinus lift versus no sinus lift Four trials of moderate quality (three trials at low and one at high risk of bias) with 102 participants evaluated short implants (5 to 8.5 mm long) as an alternative to sinus lift in bone with residual height between 4 and 9 mm. One year after loading there was insufficient evidence to claim differences between the two procedures for prosthesis failure (OR (Peto) 0.37, 95% confidence interval (CI) 0.05 to 2.68; three trials) or implant failure (OR (Peto) 0.44, 95% CI 0.10 to 1.99; four trials). There was however an increase in complications at treated sites when undertaking the sinus lift (OR (Peto) 4.77, 95% CI 1.79 to 12.71, P value = 0.002; four trials). Different sinus lift techniques Fourteen trials with 548 participants compared different sinus lift techniques. Only three comparisons included more than one trial (two trials for each). These were bone graft versus no bone graft, autogenous bone versus bone substitute, bone graft with or without platelet-rich plasma (PRP). There was insufficient evidence to claim a benefit for any of these techniques for the primary outcomes of prosthesis and implant failure. For the other reported outcomes, in a single study at high risk of bias, only bone gain was greater for the bone graft site than the site without a graft six months after augmentation, however this was not significant at 18 or 30 months.The other comparisons with single studies were rotary versus piezosurgery to open a lateral sinus window, two different bone substitutes, use or not of a membrane to seal the lateral window, one- versus two-stage lateral sinus lift, two-stage granular bone versus one-stage autogenous bone blocks, and crestal versus lateral sinus lift; two trials compared three different crestal sinus lifting techniques: rotatory versus hand malleting (patients preferred rotatory instruments over hand malleting) and hand versus electric malleting. There was no evidence of a benefit for any sinus lift procedure compared to any other for the primary outcomes prosthesis or implant failure.

AUTHORS' CONCLUSIONS

There is moderate quality evidence which is insufficient to determine whether sinus lift procedures in bone with residual height between 4 and 9 mm are more or less successful than placing short implants (5 to 8.5 mm) in reducing prosthesis or implant failure up to one year after loading. However, there are more complications at sites treated with sinus lift procedures. Many trials compared different sinus lift procedures and none of these indicated that one procedure reduced prosthetic or implant failures when compared to the other. Based on low quality evidence, patients may prefer rotary instruments over hand malleting for crestal sinus lift.

Interventions for replacing missing teeth: augmentation procedures of the maxillary sinus

BACKGROUND

Insufficient bone volume is a common problem encountered in the rehabilitation of the edentulous posterior maxillae with implant-supported prostheses. Bone volume is limited by the presence of the maxillary sinus together with loss of alveolar bone height. Sinus lift procedures increase bone volume by augmenting the sinus cavity with autogenous bone and/or commercially available biomaterials.

OBJECTIVES

To determine whether and when augmentation of the maxillary sinus are necessary and which are the most effective augmentation techniques for rehabilitating patients with implant-supported prostheses.

SEARCH STRATEGY

The Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and EMBASE were searched on 7th January 2010. Several dental journals were handsearched. The bibliographies of review articles were checked, and personal references were searched. More than 55 implant manufacturing companies were also contacted.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of different techniques and materials for augmenting the maxillary sinus for rehabilitation with dental implants reporting the outcome of implant success/failure at least to abutment connection.

DATA COLLECTION AND ANALYSIS

Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted independently and in duplicate. Authors were contacted for any missing information. Results were expressed as random-effects models using mean differences for continuous outcomes and odds ratios for dichotomous outcomes with 95% confidence intervals. The statistical unit of the analysis was the patient.

MAIN RESULTS

Ten RCTs out of 29 met the inclusion criteria. One trial of 15 patients evaluated implants 5 mm long with 6 mm diameter as an alternative to sinus lift in bone with a residual height of 4 to 6 mm. Nine trials with 235 patients compared different sinus lift techniques; of these four trials (114 patients) evaluated the efficacy of platelet-rich plasma (PRP). Due to the variety of techniques evaluated, meta-analysis was only possible of use of PRP for implant failure (two trials) and complications (three trials). No statistically significant difference was observed.

AUTHORS' CONCLUSIONS

Conclusions are based on few small trials, with short follow-up, and judged to be at high risk of bias. Therefore conclusions should be viewed as preliminary and interpreted with great caution. It is still unclear when sinus lift procedures are needed. 5 mm short implants can be successfully loaded in maxillary bone with a residual height of 4 to 6 mm but their long-term prognosis is unknown. Elevating the sinus lining in presence of 1 to 5 mm of residual bone height without the addition of a bone graft may be sufficient to regenerate new bone to allow rehabilitation with implant-supported prostheses. Bone substitutes might be successfully used as replacements for autogenous bone. If the residual alveolar bone height is 3 to 6 mm a crestal approach to lift the sinus lining, to place 8 mm implants may lead to fewer complications than a lateral window approach, to place implants at least 10 mm long. There is no evidence that PRP treatment improves the clinical outcome of sinus lift procedures with autogenous bone or bone substitutes.

Interventions for replacing missing teeth: bone augmentation techniques for dental implant treatment

BACKGROUND

Dental implants require sufficient bone to be adequately stabilised. For some patients implant treatment would not be an option without bone augmentation. A variety of materials and surgical techniques are available for bone augmentation.

OBJECTIVES

General objectives: To test the null hypothesis of no difference in the success, function, morbidity and patient satisfaction between different bone augmentation techniques for dental implant treatment.

SPECIFIC OBJECTIVES

(A) to test whether and when augmentation procedures are necessary; (B) to test which is the most effective augmentation technique for specific clinical indications. Trials were divided into three broad categories according to different indications for the bone augmentation techniques: (1) major vertical or horizontal bone augmentation or both; (2) implants placed in extraction sockets; (3) fenestrated implants.

SEARCH STRATEGY

The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE were searched. Several dental journals were handsearched. The bibliographies of review articles were checked, and personal references were searched. More than 55 implant manufacturing companies were also contacted. Last electronic search was conducted on 9th January 2008.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of different techniques and materials for augmenting bone for implant treatment reporting the outcome of implant therapy at least to abutment connection.

DATA COLLECTION AND ANALYSIS

Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted independently and in duplicate. Authors were contacted for any missing information. Results were expressed as random-effects models using mean differences for continuous outcomes and odd ratios for dichotomous outcomes with 95% confidence intervals. The statistical unit of the analysis was the patient.

MAIN RESULTS

Seventeen RCTs out of 40 potentially eligible trials reporting the outcome of 455 patients were suitable for inclusion. Since different techniques were evaluated in different trials, no meta-analysis could be performed. Ten trials evaluated different techniques for vertical or horizontal bone augmentation or both. Four trials evaluated different techniques of bone grafting for implants placed in extraction sockets and three trials evaluated different techniques to treat bone dehiscence or fenestrations around implants.

AUTHORS' CONCLUSIONS

Major bone grafting procedures of resorbed mandibles may not be justified. Bone substitutes (Bio-Oss or Cerasorb) may replace autogenous bone for sinus lift procedures of atrophic maxillary sinuses. Various techniques can augment bone horizontally and vertically, but it is unclear which is the most efficient. It is unclear whether augmentation procedures at immediate single implants placed in fresh extraction sockets are needed, and which is the most effective augmentation procedure, however, sites treated with barrier plus Bio-Oss showed a higher position of the gingival margin when compared to sites treated with barriers alone. Non-resorbable barriers at fenestrated implants regenerated more bone than no barriers, however it remains unclear whether such bone is of benefit to the patient. It is unclear which is the most effective technique for augmenting bone around fenestrated implants. Bone morphogenetic proteins may enhance bone formation around implants grafted with Bio-Oss. Titanium may be preferable to resorbable screws to fixate onlay bone grafts. The use of particulate autogenous bone from intraoral locations, also taken with dedicated aspirators, might be associated with an increased risk of infective complications. These findings are based on few trials including few patients, sometimes having short follow up, and often being judged to be at high risk of bias.