OBJECTIVETo investigate the existence of functional neuroreceptors in peri-implant bone tissue and to test the peri-implant neural feedback pathway reconstruction and its influential factors.

METHODSThree beagle dogs were involved in this study. After the extraction of 3 premolars and 1 molar of the bilateral mandible, 27 implants were placed immediately or delayed. The implants were loaded for 3 - 6 months, then sensory nerve action potential (SNAP) tests were performed. The stimulating electrode was connected to the implant or natural tooth. The recording electrode was fixed near the inferior alveolar nerve (IAN) to record the latency period and amplitude of SNAP. The specimens with peri-implant bone tissues were taken and examined by immunohistochemistry.

RESULTSSNAP of IAN could be recorded following stimulations to natural teeth and implants. The differences in SNAP amplitudes between natural teeth [(44.04 +/- 6.23) microV] and all implant groups were statistically significant (P < 0.01). Free nerve endings and nerve tract were found in the peri-implant bone tissue, but much less than those in periodontal membrane. Some nerve fibers were directly connected with implant surface.

CONCLUSIONSFunctional neuroreceptors, though much less than that of natural tooth, exist in peri-implant bone tissue. Surgical methods and loading time do not have obvious influences on peri-implant neural feedback pathway reconstruction.