Aim To compare the effect of recombinant human bone morphogenetic protein‐2 (rhBMP‐2) in an absorbable collagen sponge carrier (ACS) with autogenous bone graft for augmentation of the edentulous atrophic anterior maxilla. Methods Twenty‐four subjects were enrolled in a randomized, controlled, parallel‐group, open‐label clinical trial. Subjects either received rhBMP‐2/ACS (1.5 mg/ml) or particulated autogenous bone harvested from the mandibular retromolar region. A titanium‐mesh was used to provide space and wound stability. A guide was used to standardize clinical recordings using an analogue caliper. Alveolar ridge width was also assessed using cone‐beam computed tomography. Results rhBMP‐2/ACS yielded significantly greater radiographic horizontal bone gain compared with autogenous bone graft at immediate subcrestal levels (1.5 ± 0.7 versus 0.5 ± 0.9 mm; p = 0.01); non‐significant differences were observed at mid‐ (2.9 ± 0.8 versus 2.9 ± 0.9 mm; p = 0.98) and apical (1.7 ± 0.9 versus 1.8 ± 1.1 mm; p = 0.85) crestal levels. No significant differences in clinical horizontal bone gain were observed at 6 months between rhBMP‐2/ACS and autogenous bone graft (3.2 ± 0.9 mm versus 3.7 ± 1.4 mm; p = 0.31). Sixty‐two implants were placed after 6 month of healing with no significant differences between groups for number of implants, implant size, primary stability and survival. Conclusions rhBMP‐2/ACS appears a realistic alternative for augmentation of the edentulous atrophic anterior maxilla.

Human fresh-frozen bone block AL showed clinical compatibility for grafting procedures, although associated to slow remodeling process. Further studies are needed to define, at long term, the remodeling process chronology the clinical longitudinal results for fresh-frozen bone AL.

A monoclonal antibody (mAb TRA 104) raised against mouse testicular germ cells was able to recognize the nuclei of testicular germ cells at all the stages of differentiation from embryonic gonocytes to spermatids and did not react with any somatic cells. The antigen recognized by mAb TRA 104 was exclusively present in testicular extracts. The molecular weights and isoelectric point (pI) of the antigens determined by Western blotting analysis were 60-110 kDa and 7.2, respectively. This antigen(s) is referred to as a germ cell-specific nuclear antigen(s) (GENA) since GENA was first detected specifically in the genital ridge at around 12 days of gestation by Western blotting analysis. In the testis, the expression increased gradually until adulthood whereas it was lost in the ovary by postpartum day 5. Thus, GENA is a molecule(s) exclusively present in the nuclei of germ cells and may be a useful marker with which to study the mechanism of germ cell development and differentiation at the molecular level.

Allogeneic bone block grafts may be an option in cases where a limited amount of augmentation is needed, and the future implant can be expected confined within the inner aspect of the bone block. However, the clinical impact of the relatively poor graft incorporation on the long-term performance of oral implants placed in AL grafts remains obscure.

AL block bone graft architecture influences significantly its dimensional incorporation and remodeling. Compared with AT bone graft, a small portion of the AL block consists of vital bone 6-8 months after grafting. Cortical AL blocks seem to show the least amounts of vital bone, while corticocancellous AL blocks seem to undergo more resorption over time.