The Study Of Effects And Mechanisms Of Calcineurin Inhibitor On Implant Osseointegration

Chapter1The biological effects of calcineurin on the osteoblast derived from the maxilla-alveolar bone of Sprague-Dowley RatsObjective:To investigate the effects of tacrolimus and CsA on the proliferation, differentiation and mineralization of osteobiasts derived from maxilla-alveolar bone of Sprague-Dowley RatsMethods:The osteobiasts were cultivated from the maxilla-alveolar bone of Sprague-maxilla bone of6-week-old Sprague and Dowley rats. The passage cells were identified with the Gimsa staining, AKP staining and Alizarin red staining. The cells were grouped into TAC-LOW(tacrolimus10μg/L), TAC-HIGH (tacrolimus1000μg/L), CYSA(cyclosporine A1000μg/L) and CONTROL. The proliferation of osteoblasts were measured with MMT. The correlative expression of BGP, Type I collagen, c-fos and c-jun of1week and3weeks were examined with qRT-PCR. The concentration of ALP and calcium of culture fluid were measured in the7th,10th and14th day after medicated. In the28th day of cultivation, the mineralized nodule formation was observed afteralizarin-red staining.Results:The ALP level of10th and14th day reduced in group CYSA and TAC-HIGH, while the calcium level elevated. In group TAC-LOW, the ALP level of14th day elevated and calcium level reduced. In the28th day the mineralized nodules formation enhanced. The enhanced expression of c-fos, c-jun, BGP and Type I collagen were observed in TAC-LOW.Conclusion:Low dosage of tacrolimus promots the proliferation, differentiation and mineralization of osteoblast. High dosage of tacrolimus enhances proliferation in early period but inhibits differentiation and mineralization. CsA inhibits the proliferation, differentiation and mineralization of osteoblast. Chapter2Effects of two different dosage of tacrolimus on BMD, bone microstructure and metabolism of Sprague-Dowley ratsObjective:To investigate effects of two different dosage of tacrolimus on BMD, bone microstructure and metabolism of Sprague-Dowley rats.Methods:306-week-old Sprague-Dowley rats were grouped: TAC-LOW(10μg/L), TAC-HIGH(1000μg/L) and NS(Normal Saline). The serum ALP, BGP, NTX and soluable RANKL were measured in the1st,16th,31st,46th,61st,76th and91st day after medication. In the end of3rd month the proximal tibia and maxilla-alveola bone were removed and examined with microCT.Results:In TAC-LOW, BMD of proximal tibia reduced but the maxilla-alveola bone kept no measureable changes. ALP, BGP, NTX and soluble RANKL level elevated. Tb.N and MAR increased but Tb.Th decreased. In TAC-HIGH, BMD of both proximal tibia and mixilla-alveola bone reduced. ALP and BGP level decreased but NTX and soluble RANKL kept increasing. The reduced Tb.Th and MAR and augmented ES/BS were observed.Conclusion:Low dosage of tacrolimus enhanced bone formation and bone remodeling. In maxilla-alveola bone there was high turn-over changes but BMD decreases little. High dosage of tacrolimus enhanced bone formation in early stage but immediately it accelerates bone resorption, the effects results in reduced BMD of bone tissue.Chapter3Effects of two different dosage of tacrolimus on titanium implant osseointegration of Beagle’s dogObjective:To evaluate effects of two different dosage of tacrolimuson titanium implant osseointegration of Beagle’s dog.Methods:66-month-old Beagle’s dogs were grouped:TAC-LOW(10μg/L), TAC-HIGH(1000μg/L) and NS (Normal Saline). After medicated for2months, the tatanium implant was inserted. After3months, the stability of implant was measured with an osstell mentor. Then bone samples with implant were removed. The interface was examined with microCT and optical microscope afterthe toluidine blue O staining and HA staining. The EDS/SEM was performed to analyze the elementcomposition.Results:There was no difference in implant stability between TAC-LOW and NS. Elemental composition analysis showed higher content of titanium in bone tissue around the implant.The loosening implant and malunited wound were seen in TAC-HIGH. There was less titanium but higher content of carbon and oxygen in bone tissue around the implant.Conclusion:The titanium implant osseointegration could be reached under administration of low dosage of tacrolimus(10μg/L). Higher dosage of tacrolimus results in implant failure.Chapter4A case series study of dental implant therapy in organ transplantation patients who take calcineurin inhibitorsObjective:To investigate the feasiblity of implant therapy in organ transplantationpatients who take tacrolimus as immunosuppressant.Methods:13edentulous liver transplantation patients, who mostly took calcineurin inhibitors for at least2years, were restored with implant. The observation peroid was1-3years. MBL and PD of every implant3rd months and subsequent every year was evaluated with radiological examination. The stability of every implant was examined with Osstell Mentor.Results:There was no loosening or missing implant in all cases. Except3teeth loosened, all patient were satisfied with their implant-suppoted prostheses. Conclusion:It can be concluded cautiously that the transplantation patients who take regular dosage of tacrolimus could take implant prosthesis as alternative method.