Crestal bone loss minimized when following the crestal preparation protocol: a histomorphometric study in dogs.

Initial breakdown of the implant-tissue interface generally begins at the crestal region in successfully osseointegrated implants. The purpose of this study was to evaluate the effect on crestal bone loss (CBL) around implants specially developed for immediate loading with a unique crestal drill. After 8 weeks postextraction, 6 young male mongrel dogs received 48 implants (XiVE) in the region corresponding to the 4 mandibular premolars. The implant sites were prepared according to the manufacturer's protocol with conventional standard drills. Before implant placement, the crestal drill was used in the experimental group but not in the control group. After a healing period of 12 weeks, the dogs were sedated and euthanized. Through linear measurements, from the top of the implant to the first bone-implant contact, the amount of CBL was determined. The histomorphometric results of CBL (mean +/- SEM) were 0.88 +/- 0.13 mm (range 0.0-3.0 mm) in the experimental group and 1.69 +/- 0.17 mm (range 0.0-4.2 mm) in the control group. The difference was statistically significant (P < .05) when the implants were used as the experimental units. The statistical analysis also revealed significance when the dogs were used as the experimental units (P < .05). When the median was used for analyses, the CBL was 0.44 mm for the experimental group and 1.91 mm for the control group. Crestal bone loss was minimized when the crestal preparation protocol was carefully followed by using the osseocondensating XiVE implant system.