In the cranial part of the biopsy, some osteoid islands with osteogenic activity were detected, possibly caused by osteoinductive properties from the lifted bony trap-door. In the present study, histomorphometric analyses revealed that the vital bone volume was higher in the 9-month healing time group than in the 12-month healing time group, while one would expect to find more newly formed bone in time as more of the bone substitute resorbs. As the mean original native alveolar bone height is 6.4 mm in the 9-month group and 4.4 mm in the 12-month group and augmented portion of the 12-month group (9.3 mm) is higher than the 9-month group (7.5 mm), this may have a negative impact on the relatively smaller portion of the bone volume of the total biopsy in the 12-month group. This is a limitation of the present study.

However, the average 2 mm of difference in the native bone height between the 9- and 12-month groups does not fully explain the difference in BT/TV that was found between the two groups. Furthermore, the thickness of the bone trabeculae decreased suggesting that at 12 months, bone turnover returns to a relatively normal bone remodeling status, indicative of a new balance in bone tissue. However, woven bone (data not shown) and the remnants of the BCP were still present at 12 months, contradicting this hypothesis. Nevertheless, from a histological and histomorphometric perspective in the present study, a 9-month healing time may be the optimal time for the placement of dental implants. Although the sample size of the two groups is small, multiple dental implant placements deliver sufficient data for evaluation. The 12-month period from MSFE to implant placement(s) is considered to be a long time. Most patients are not willing to wait that long, which makes these bone samples very scarce and therefore valuable for long-term observations. The implication of the small sample size is that this study has an observational nature and, therefore, only descriptive statistics are presented.