Effect of absorbable membranes on sandwich bone augmentation.
OBJECTIVE
This study was conducted to evaluate the effect of barrier membranes on sandwich bone augmentation (SBA) for the treatment of implant dehiscence defects.


METHODS
Twenty-six implant-associated buccal dehiscence defects in 22 patients were treated according to the SBA concept - mineralized human cancellous allograft (inner layer), mineralized human cortical allograft (outer layer) and coverage with barrier membrane. The defects were randomly assigned to the bovine collagen membrane (BME) group; acellular dermal matrix (ADM) group; and no membrane group. Measurements at baseline and 6 months re-entry included defect height (DH: from smooth-rough junction to the most apical part of the defect), defect width (DW: at the widest part of the defect), and horizontal defect depth (HDD: at three locations - smooth-rough junction, middle, and most apical portion of the defect). All measurements were taken from a reference stent. Statistical analyses were performed for comparison of intra- and inter-group comparisons.


RESULTS
All implants placed were successfully osseointegrated. DH at baseline for three groups were not significantly different (P=0.858). Mean % DH reductions for ADM, BME, and control groups at 6 months were 73.9+/-17.6%, 68.1+/-30.1%, and 63.6+/-23.9%, respectively, with no significant difference among the groups (P=0.686). Mean horizontal bone gain, however, was significantly greater for membrane groups (1.7 mm for ADM, 1.6 mm for BME) compared with control group (1 mm) (P=0.044). Implant exposure resulted in significant reduction in total height gain (79.1+/-14.3% vs. 57+/-23.5%, P=0.021).


CONCLUSIONS
Within the limit of this study, it is concluded that SBA technique achieved predictable clinical outcomes. The addition of absorbable membranes enhanced bone gain in thickness compared with membrane-treated sites.
Park
Sang-Hoon
SH
School of Dentistry, University of Maryland, Baltimore, MD 21201, USA. sbpark@umich.edu
Lee
Kwang-won
KW
Oh
Tae-Ju
TJ
Misch
Carl E
CE
Shotwell
Jeffrey
J
Wang
Hom-Lay
HL
D020341:Absorbable Implants; D000328:Adult; D000368:Aged; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D000704:Analysis of Variance; D000818:Animals; D001861:Bone Regeneration; D016025:Bone Transplantation; D002417:Cattle; D003094:Collagen; D003758:Dental Implantation, Endosseous; D019250:Dental Implants, Single-Tooth / Q000009:adverse effects; D005260:Female; D016557:Guided Tissue Regeneration, Periodontal / Q000379:methods*; D006801:Humans; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D016037:Single-Blind Method; D017768:Skin, Artificial; D013529:Surgical Wound Dehiscence / Q000209:etiology / Q000601:surgery
C440568:Alloderm; D008567:Membranes, Artificial; D003094:Collagen