Preliminary Research Of The Effects Of Different Implant Surfaces On Nerve Regeneration

Background:In the1960s, the"Osseointegration" theory raised by Branemark laidthe biological basis of the moden oral implantology. Nowadays,implantdenture has been widely used in the restoration of dentition defect andedentulous. In the1990s,"osseoperception" was proposed, it wasconsidered to be a special body sensing function in the case of lack ofperiodontal proprioceptors.In the natural teeth, the bite force conductsproprioceptor perception through the periodontal ligament, and transfersto the cerebrum and thus regulates mandibular movement.The implantsurroundings are lack of periodontal ligament,and lack of periodontalproprioceptors, theoretically, it will be lack of similar perception asnatural teeth, however, scholars found that the implant denture patients’sense of touch, vibration sense and physical ability to distinguish issimilar to natural teeth. But some scholars have found that the maximumbite force, the side effects of the implant denture implant bite force wassignificantly greater than the contralateral dentition bite force. Theexcessive bite force may result in the absorption of the bone around theimplant, temporomandibular joint disease or even breakage of the implant.Therefore,the research of implant nerve regeneration has great significance.The implant surface characteristics has been a hot research field for along time. Many technologies, including the smooth surface,theelectrolytic etching techniques, sand-blasted large grift acid-etching, acidetching, hydroxyapatite coating, titanium plasma spraying are used tooptimize the properties of the implant surface.Objective:This study observes the effects of four implant surfaces (S, EE, SLA,HA) on nerve regeneration and nerve conduction performance, in order toprovide an objective basis to investigating the mechanism of nerveregeneration. Through the analysis, in order to initially speculate animplant surface topography which is more conducive to the regenerationof peripheral nerve, and provide a theoretical reference for the implantmaterial performance improvement and the choice of clinical types.Methods:Titanium implant specimens were treated by different treatments toget smooth group,electrolytic etching group, sand-blasted large griftacid-etching group and hydroxyapatite coating group implants. Afterpreparation, using scanning electron microscope to observe thecharacteristics of different implant surface micromorphology. Three dogswere used as experimental animals, removing the second and the thirdmandibular premolar of each side,and then implanted four implants at the same period according to a certain order.1,2, and3months afterimplantation,BL-420E Biological Experimental was used to detect thedetermination of the amplitude of the inferior alveolar nerve sensorynerve action potential in a series of stimulus intensity.After the lastelectrophysiological testing,the animals were killed,and X-ray projectionis proceeded to observe the position of the implants. Using SPSS19.0statistical packages for statistical analysis.Results:1.Under the scanning electron microscope, S, EE, SLA and HAsurface micromorphology were different in significance. S group waslack of obvious steric structure.EE group presented a uniform shallowbowl-shaped recess level micron holes, on the basis of a micron holes,covered with nanopores, and at the basal part of micron holes, nanoporeswere at visible presence, a small number of nanopores merged andconnected into a hole.The SLA group had a lot of depression on thesurface, and also had cavity,cracks and sharp edges,it was irregular inshape, size and shades.The HA group surface had different size shades ofgranular protrusions and depressions of different shades.2.At1months, four groups of SNAP amplitude increased graduallywith the increase of the intensity of stimulation, and the amplitude of theHA group was significantly higher than that of EE group,SLA group andS group(P <0.05), had statistically significance; volatility of EE group was higher than SLA group and S group(P <0.05),was statisticallysignificant; volatility of the SLA group and S group were similar(P>0.05),was lack of statistical significance.3.At2months and3months, four groups of SNAP amplitudeincreased with the increase of the stimulus intensity gradually, when thestimulus intensity≥800mV,the SNAP amplitude of each group graduallystabilized, and each group comparisons were not statistically significantwhen compared with each other(P>0.05).4. In each group,1month compared with2months and3monthsrespectively,there were significantly different, P <0.05; when2monthsand3months compared, P>0.05, was lack of statistical significance, andat1month the curve was presented to be gradual increasing,and theSNAP was significantly lower than2months and3months at the samestimulus intensity,2months and3months group curves were similar inthe shape, the volatility tended to be stable when the stimulus intensitywas more than800mV, the SNAP amplitude values of four groups werealmost the same, about11.20mV.Conclusion:1.The regeneration and reconstruction of nerve are gradual process,it merely forms parts of the nerve endings or is unable to functionnormally in their early stages.2.The implant peripheral nerve healing and regeneration of the initial stage of different implant surfaces are significant difference, the SNAPexpressed as HA> EE> SLA=S. Indicating that the nerve regenerationprocess may be strengthened by hydroxyapatite coating implant surfaceor electrolytic etching implant surface.3.At2and3months after implantation,the nerve regenerationprocess is nearly completed,different implant surfaces has no significanteffects on the number or the function of final peripheral nerve formation.