Background: Root conditioning with Enamel matrix derivative (EMD) is a standard protocol for periodontal regeneration. Recent studies have suggested that enamel matrix proteins play a critical role in bone formation and that EMD liquid mixed with bone grafts may stimulate bone regeneration. Natural bovine bone (NBB- Cerabone®) is relatively new bone graft and effect of NBB combined with EMD liquid remains unclear.

Aim/Hypothesis: The present study aimed to evaluate osseointegration and bone formation after application of NBB combined with EMD liquid (Osteogain®) in buccal bone defects at dental implants.

Material and Methods: Six beagles were used in the present study. Three months after posterior mandibular tooth (P2, 3, 4 and M1) extraction, three titanium implants (3.3 mm x 8.0 mm) were placed and a with buccal bone defect (3.0 x 5.0 mm) was created+ two implants on one side and one implant on the contralateral side. Buccal defects were randomly assigned to one of the following treatments- Group 1, NBB+ Group 2, NBB + EMD liquid and Group3, Control, where no graft materials were applied. A bioresorbable membrane was used to cover the defects in all groups. After 3 months of healing, histomorphometric measurements were performed by analysing (1) bone implant contact (BIC+ %) and first-BIC (mm), (2) new bone area (NBA+ mm2) and (3) proportions of various components (%), such as mineralised tissues (MT), fibro-vascular connective tissues (FCT) and residual bone-graft materials, inside the buccal bone defects as a region of interest.

Results: NBA, BIC and first-BIC in the NBB (6.9 ± 2.3 mm2, 52.8 ± 11.7% and 1.2 ± 0.2 mm, respectively) and NBB + EMD-liquid (8.0 ± 1.5 mm2, 57.4 ± 7.1% and 0.4 ± 0.1 mm, respectively) groups were significantly greater than NBA, BIC and first-BIC in the control group (2.6 ± 1.4 mm2, 20.5 ± 5.6% and 2.0 ± 0.1 mm, respectively). Furthermore, histological analysis revealed that first-BIC was significantly higher in the NBB + EMD-liquid group than in the NBB group (P = 0.0013). However, no significant difference was observed in the percentage of MT among the groups (32.8 ± 15.6%, 25.3 ± 14.0% and 26.5 ± 20.1%). The percentage of FCT was higher in the control group (73.4 ± 20.1%) than the percentage of FCT in the NBB and NBB + EMD-liquid groups (36.2 ± 8.9% and 34.4 ± 9.3%, respectively) + however, it was not significantly different between the NBB and NBB + EMD-liquid groups as well as between the NBB and control groups (P = 1.00, 0.064).

Conclusion and Clinical Implications: Within the limits of this study, NBB grafting materials with or without EMD liquid can significantly enhance the volumetric area of alveolar ridge augmentation as well as BIC% in dental implants with buccal bone deficiency compared with no grafting. The additional use of EMD liquid appears to enhance fBIC, thereby improving osseointegration around dental implants. NBB with EMD liquid can be recommended for guided bone regeneration in implants with buccal bone defects.