| Objective:This research aims to explore the best power of low-power laser irradiation on implant-osseointegration by observation,analysis of histology and bone histomorphometry, and provide a further scientific basis for the clinical application of a low-power laser in Oral Implantology.Methods:6 female Beagle dogs were selected according to international standards. In accordance with the surgical implanting method of BLB implant system, surgeries were operated on each dog from both sides of the tibia, four implant sockets were implanted in 4 BLB (?) 3.3 x 8mm implant, every side 4 planting interval 2cm,which were divided into A, B, C,D group randomly. D group which as control group was not irradiated. A(15mW),B(25Mw),C(35Mw) groups for the experimental group were immediately irradiated after surgery.The period of irradiation is two weeks,20min/once, per day. Specimens were obtained 1,2 and 3 months after implantation, from two animals at each time point.Before killing the animals tetracycline double labeling were exposed. Making the 16 tibial implant specimens, for the general observation and production of bone implants with grinding plate, the semi-automatic digital image analysis system under the analysis of bone grinding, measuring and recording percent labeled perimeter(%L.Pm) and mineral apposition rate (MAR), after Goldner's trichrome the bone-implant contact(BIC) was measured.Analyzing the variance of data and then obtain the experimental results.Results:1. Surgical implants:The surgery of implanting implants in Beagle dog tibia went smoothly without any abnormal reaction for laser irradiation. All the dogs survived the surgery and behaved normally, with their wounds healing well and no inflammatory response.2. General observation of specimens. More new bones grew, with smooth surface, around the implants in the A,B groups than those of in the C,D groups.3. Roentgenologic visualtation of specimens.any of the implants which were implanted in the same direction were without devulvium.4. Fluorescence microscope observation and bone histomorphometry analysis:One month after operation,there was a statistically significant difference between A,B and C,D groups in mineral apposition rate (MAR) and percent labeled perimeter(%L.Pm) (p<0.05).The MAR and %L.Pm of A,B groups was significantly higher than C,D groups, there was no statistically significant difference between A and B group (p>0.05). and there was no statistically significant difference between C and D group either. Two and three months after operation there was no statistically significant difference between among four groups (p>0.05). InA,B groups the percent labeled perimeter(%L.Pm) and mineral apposition rate (MAR) of 1 month after operation was significantly higher than it of 2,3 months after operation (p<0.05).Between C,D groups the significant difference was found only between 1 and 3 months(p<0.05). 5. Optical microscope observation and histomorphology analysis:On bone-implant contact(BIC) one and two months after operation there was no statistically significant difference between among four groups (p>0.05). Three months after operation there was a statistically significant difference between between A,B and C,D groups (p<0.05). The bone-implant contact (BIC) of A,B groups was significantly higher than C,D groups. But there was no statistically significant difference between A and B group (p>0.05) and there was no statistically significant difference between C and D group either. (p>0.05).Conclusions:1. Low-power laser can promote early peri-implant bone formation,enhance the initial implant stability, so make the implant more stable.2. Low-power laser can promote the formation of bone-implant interface and, to some extent promote the mature of bone tissue and shorten the osseo-integration time.3. Two weeks'irradiation of low-power laser play a significant promotion role in implant-osseointegration and the effect of 15mW and 25mW low-power on increasing the activity and the proliferation of osteoblasts aroud implant at early period is better.4. Two weeks'irradiation of low-power laser play a significant promotion role in implant-osseointegration and the effect of 15mW and 25mW low-power on increasing final bone-implant contact (BIC) is better. |
PDF Full Text Request