The influence of collagen membrane and autogenous bone chips on bone augmentation in the anterior maxilla: a preclinical study.

OBJECTIVES

To evaluate the effect of a resorbable collagen membrane and autogenous bone chips combined with deproteinized bovine bone mineral (DBBM) on the healing of buccal dehiscence-type defects.

MATERIAL AND METHODS

The second incisors and the first premolars were extracted in the maxilla of eight mongrels. Reduced diameter, bone-level implants were placed 5 weeks later. Standardized buccal dehiscence-type defects were created and grafted at implant surgery. According to an allocation algorithm, the graft composition of each of the four maxillary sites was DBBM + membrane (group D + M), autogenous bone chips + DBBM + membrane (group A + D + M), DBBM alone (group D) or autogenous bone chips + DBBM (group A + D). Four animals were sacrificed after 3 weeks of healing and four animals after 12 weeks. Histological and histomorphometric analyses were performed on oro-facial sections.

RESULTS

The pattern of bone formation and resorption within the grafted area showed high variability among the same group and healing time. The histomorphometric analysis of the 3-week specimens showed a positive effect of autogenous bone chips on both implant osseointegration and bone formation into the grafted region (P < 0.05). The presence of the collagen membrane correlated with greater bone formation around the DBBM particles and greater bone formation in the grafted region after 12 weeks of healing (P < 0.05). The oro-facial width of the augmented region at the level of the implant shoulder was significantly reduced in cases where damage of the protection splints occurred in the first week of healing (P < 0.05).

CONCLUSIONS

The addition of autogenous bone chips and the presence of the collagen membrane increased bone formation around DBBM particles. Wound protection from mechanical noxa during early healing may be critical for bone formation within the grafted area.