الفهرس 
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Abstract
BACKGROUND: The success of implants is associated first with their osseointegration, and later on with their survival rate. In recent years, many efforts have been exerted to develop implant design, geometry, materials and techniques to enhance the osseointegration process and also to increase the success rate of implant procedures. Advanced techniques, like leukocyte and L-PRF and LLLT, have been developed to enhance the osseointegration around dental implants.
AIM OF THE STUDY: This study aims at: 1- Evaluating the bone osseointegration process around dental implants after using advanced implant techniques like the application of LLLT and L-PRF which has become well-accepted adjuvant tools to enhance the osseointegration process. 2- Comparing between the various advanced techniques in dental implant procedures to figure out which technique will achieve the best results. METHODS: The study was conducted on a random sample of 40 male patients. 40 dental implants were placed in the posterior areas of the lower jaws of the patients, with one implant for each patient. Patients were divided randomly into 4 groups, with 10 patients in each group; Groups; A: Control, B: Treated with Diode Low Level Laser (A laser device class IIIB, Gallium-AluminumArsenide Diode laser that emits wavelength of 808 nm), C: Treated with Growth Factor (L-PRF) and D: Combined application of both (LLLT+LPRF). They were assessed clinically and radiographically using CBCT at the baseline of 1 week after the implant insertion (the day of suture removal), followed by another one after 6 weeks from implant insertion, and by another one after 12 weeks from the implant insertion, to evaluate the RBD around each implant. INCLUSION CRITERIA: 1-Patients were males with missed lower posterior teeth. 2-The working areas were edentulous for at least 6 months. 3- The patients’ ages ranged from 30 to 40 years old. 4-The study was performed on the lower jaw. EXCLUSION CRITERIA: 1- Patients with excessive bone loss. 2- Diseases affecting healing process (e.g. DM, Thyroid disease and different hematological diseases that could affect platelet counts). 3- Females were excluded to avoid any hormonal changes which may affect the result of the study. 4- Patients who receive radiotherapy or chemotherapy. RESULTS: The results showed significant differences between all groups over different measured times. All the groups showed improvement in comparison with Control group, where L-PRF group showed the best result followed by (LPRF+LLLT) group, while the LLLT group showed the least improvement in comparison with both LPRF group and (L-PRF+LLLT) group. › DISCUSSION: Osseointegration is described as an effective interaction between bone tissue and the implant surface. Osseointegration of titanium implants in rats was conducted by Haga et al. This process is characterised by bone resorption by osteoclasts, followed by bone formation by osteoblasts. Few days after the implant placement, osteoclast cells become more prominent in number and in action than osteoblast cells to start bone resorption. 1 month after implant placement, the osteoblast cells become more active to start the osseointegration process. from 1.5 to 2.5 months after the placement of implants, the formation of bone tissue by osteoblast cells proceeds in the direction of the damaged bone containing empty osteocyticlacunae.The portion of neoformed bone exhibits characteristics of spongy bone. 3 months after implant placement, there was an absence of empty osteocytic lacunae. The area of pre-existent bone has been replaced by neoformed bone containing intact osteocytes. The neoformed bone presents the morphological characteristics of compact bone. › › The most challenging issue about LLLT is to define the effective dose. Several studies in the literature promote low-level laser therapy as a useful procedure to improve osseointegration with doses used between 2 and 54 J. Accordingly, we use 20 J/cm3. Laser spot area should be known to have an opinion about the dose of the energy given to the tissue. We should measure the delivered energy regarding the volume of the region and not just the area of the region. The energy dose delivered to the bone was calculated according to the volume of the implant using the following equation: Energy dose (J/cm3) = W.T/cm3 to ensure the delivery of sufficient energy to the bone surrounding the implant. The frequently used lasers in the previous studies range from 670 to 1,064 nm. In the current study, low-intensity Gallium-Aluminum-Arsenide laser with wavelength 808 nm was used. In the current study, The Laser group shows improvements in the RBD after 6 weeks in comparison with the control group. However, Laser group, showed lower results of RBD in comparison with L-PRF group. This can be explained by a study was made by Burcuetal.This study used 38 male albino Wistar rats. It aimed at evaluating the effects of 820 nm diode laser on osteoclastic and osteoblastic cell proliferation-activity and RANKL/OPG release during orthodontic tooth movement. That study concluded a very important fact about LLLT, which is Low-level laser therapy is known to be a stimulator of the current biological process in tissue.Based on this fact Burcu et al., used this fact to explain why osteoclastic activity increased in laser groups while osteoblastic activity was similar between groups on the third day of his experiment. Also, at the end of his experiment, because bone formation had already started, the number of osteoblasts was increased in the laser groups. Moreover, Glinkowski and Pokora indicated that LLLT to bone increased phagocytosis and cytokine synthesis (IL-1, TGF-β) via accelerating macrophage migration. According to Karu et al., he said that the mitochondrial cytochromes absorb the photon energy, and this absorption improves the activity of the cells via increasing ATP synthesis. Because osteoclasts are multinuclear cells with mitochondria of high activity, they are readily affected by low-level laser radiation. This also explains the higher resorption levels in the irradiated animals in Burcu et al., study. from the previous studies, we can conclude that : (a) The decrease in the RBD at 6th week measurments in the control group in the current study is due to the pronounced activity of the osteoclast cells that are active in the first month after the implant placement. (b) In Laser group, there was a slight increase in the RBD after 6 weeks because laser biostimulation affects both osteoclast cells positively in the first days after the implant placement and osteoblast cells which became prominent at the end of the first month after the implant placement to compensate the bone loss in the first month and increases the RBDs slightly at the end of the 6th week. Regarding the L-PRF group, the improvement efficiency percentage was the best between the 4 groups due to: (1) PRF stimulated healing, osteoblast cells, and limited the osteoclastogenesis. (2) Anil Kumar et al., reported that PRF inhibited both the formation and differentiation of osteoclast cells. (3) Anil Kumar et al., also reported that PRF molecular mechanism of action was related to the apoptosis induction through intrinsic mitochondrial pathway by activating caspases-9, -3 and -7 which are the most prevalent caspases and they are responsible for the majority of apoptotic effects. Despite the improved RBD in both groups treated with Laser and L-PRF, when we combine them, the density was improved but to less extent than the group used the L-PRF alone; and this means that the Laser radiation stimulated the osteoclasts which negatively affected the role of L-PRF slightly. This means that the LLLT has an inhibitory role on the PRF effect. RBD increases after 12 weeks in the 4 groups because, within the period of 1.5 to 2.5 months after the placement of implants, the activity of the osteoclast cells decreases and the activity of osteoblast cells increases to start the process of bone formation. CONCLUSION: 1-The osseointegration of dental implants can be clearly enhanced using advanced techniques like LLLT and L-PRF. These advanced techniques could increase the success rate of dental implants. 2-L-PRF has a more positive effect on the osseointegration of dental implant than LLLT. 3-The combined application of L-PRF and LLLT could enhance the osseointegration of dental implant but to a lower extent than applying L-PRF alone. 4-Moreover, the combined application of L-PRF and LLLT could enhance the osseointegration of dental implant more than applying LLLT alone.