Search

Statement of problem Strontium has been validated for potent bone-seeking and antiosteoporotic properties and elicits a potentially beneficial impact on implant osseointegration in patients with osteoporosis. However, the efficacy of strontium supplementation on improving new bone formation and implant osseointegration in the presence of osteoporotic bone is still unclear. Purpose The purpose of this systematic review was to comprehensively assess the efficacy of strontium supplementation, encompassing oral intake and local delivery of strontium, on implant osseointegration in patients with osteoporosis. Material and methods Searches on electronic databases (MEDLINE or PubMed, Web of Science, EBSCO, Embase, and Clinicaltrials.gov ) and manual searches were conducted to identify relevant preclinical animal trials up to June 2020. The primary outcomes were the percentage of bone-implant contact and bone area; the secondary outcomes were quantitative parameters of biomechanical tests and microcomputed tomography (μCT). Results Fourteen preclinical trials (1 rabbit, 1 sheep, and 12 rat), with a total of 404 ovariectomized animals and 798 implants, were eligible for analysis. The results revealed a significant 17.1% increase in bone-implant contact and 13.5% increase in bone area, favoring strontium supplementation despite considerable heterogeneity. Subgroup analyses of both bone-implant contact and bone area exhibited similar outcomes with low to moderate heterogeneity. Results of biomechanical and μCT tests showed that strontium-enriched implantation tended to optimize the mechanical strength and microarchitecture of newly formed bone despite moderate to generally high heterogeneity. Conclusions Based on the available preclinical evidence, strontium supplementation, including local and systemic delivery, showed promising results for enhancing implant osseointegration in the presence of osteoporosis during 4 to 12 weeks of healing. Future well-designed standardized studies are necessary to validate the efficacy and safety of strontium supplementation and to establish a standard methodology for incorporating Sr into implant surfaces in a clinical setting.

The spectrum of bone lesions in axial spondyloarthritis is of great interest. With inflammation and mechanical influence concurrence in the background, both tissue gain and tissue loss in a particular bone area can occur simultaneously. Moreover, if vertebral bone mass loss, perhaps, can be easily explained by chronic systemic inflammation, the reason of its gain, observed in axial spondyloarthritis remains a mystery. It is unclear whether it is a consequence of enhanced recovery processes after injury, adaptation to altered mechanical stress, response to inflammatory cells activation or cytokines, produced by them, or changes in Wnt signaling pathways (for example). Whether these factors act individually or collectively is also unclear.

OBJECTIVES The present study was performed to compare the effectiveness of Ankaferd Blood Stopper® (ABS) with enamel matrix derivatives (EMD) for treating fenestration defects in rats. MATERIALS AND METHODS Forty-eight male Wistar rats were randomly divided into six groups (each n = 8). Fenestration defects were created in all rats, to which ABS, EMD, or saline (S) was then applied. The rats were grouped and sacrificed at one of two different time points, as follows: ABS-10-group, ABS-treatment/sacrifice on day 10; EMD-10-group, EMD-treatment/sacrifice on day 10; S-10-group, S-treatment/sacrifice on day 10; ABS-38-group, ABS-treatment/sacrifice on day 38; EMD-38-group, EMD-treatment/sacrifice on day 38; and S-38-group, S-treatment/sacrifice on day 38. Then, histomorphometric analysis including measurements of new bone area (NBA) and new bone ratio (NBR), and immunohistochemical analysis including the determination of osteopontin (OPN) and type-III-collagen (C-III) expression were performed. RESULTS The NBA and NBR were significantly higher in the ABS-10-group and EMD-10-group compared to the S-10-group (p

Objective:The current study aimed to assess the relationship between protein intake and bone parameters among dynapenic-obese older adults.Design:The current study is a secondary analysis with an a posteriori and exploratory design.Setting:Subjects were recruited from the community via social communication (flyers and meetings in community centres) in the Great Montreal area.Participants:Twenty-six subjects were divided a posteriori into two groups according to their usual protein intake: PROT−: < 1 g/kg per d (n 13; women: 53·8 %; 66·5 (sd 3·3) years) and PROT+: > 1·2 g/kg per d (n 13; women: 61·5 %; 67·2 (sd 2·7) years).Results:Both groups were comparable for age (PROT−: 66·5 (sd 3·3) v. PROT+: 67·2 (sd 2·7) years, P = 0·61) and gender (women: PROT−: n 7; 53·8 % v. PROT+: n 8; 61·5 %, P = 0·69). The PROT− group had a higher marrow area (P = 0·049), a greater bone compressive strength (P = 0·048) and a larger total bone area (P = 0·045) than the PROT+ group. However, no significant difference between the two groups was observed regarding body composition (fat and lean masses) or muscle composition.Conclusions:A lower protein intake seems to be associated with bone sizes, which influence bone strength, but do not influence bone density among dynapenic-obese older people.

Objectives Variation in human trabecular bone morphology can be linked to habitual behavior, but it is difficult to investigate in vivo due to the radiation required at high resolution. Consequently, functional interpretations of trabecular morphology remain inferential. Here we introduce a method to link low- and high-resolution CT data from dry and fresh bone, enabling bone functional adaptation to be studied in vivo and results compared to the fossil and archaeological record. Materials and methods We examine 51 human dry bone distal tibiae from Nile Valley and UK and two pig tibiae containing soft tissues. We compare low-resolution peripheral quantitative computed tomography (pQCT) parameters and high-resolution micro CT (μCT) in homologous single slices at 4% bone length and compare results to our novel Bone Ratio Predictor (BRP) method. Results Regression slopes between linear attenuation coefficients of low-resolution pQCT images and bone area/total area (BA/TA) of high-resolution μCT scans differ substantially between geographical subsamples, presumably due to diagenesis. BRP accurately predicts BA/TA (R2 = .97) and eliminates the geographic clustering. BRP accurately estimates BA/TA in pigs containing soft tissues (R2 = 0.98) without requiring knowledge of true density or phantom calibration of the scans. Discussion BRP allows automated comparison of image data from different image modalities (pQCT, μCT) using different energy settings, in archeological bone and wet specimens. The method enables low-resolution data generated in vivo to be compared with the fossil and archaeological record. Such experimental approaches would substantially improve behavioral inferences based on trabecular bone microstructure.

Purpose This systematic review and meta-analysis aims to synthesize evidence relating to the effects of TiO2 nanotubes on osseointegration in animal models. Materials and methods The focused question was "Does the preparation of TiO2 nanotubes on the surface of implants enhance osseointegration?" Searches were performed for relevant manuscripts up to September 2019 using the PubMed, Embase, Scopus and Google Scholar databases with terms such as "TiO2 nanotubes" in combination with "osseointegration", "osteogenic", "osteogenesis", and "bone regeneration". The titles, abstracts and full texts of the manuscripts were reviewed in accordance with the eligibility criteria. The meta-analysis were then performed to analyze the effects of TiO2 nanotubes in bone-implant contact (BIC) and biomechanical tests. Results Fourteen manuscripts were included for the systematic review and meta-analysis. Eleven studies showed that the results of a histological analysis, micro-CT evaluation and biomechanical tests were significantly higher near TiO2 than titanium. The meta-analysis demonstrating similar results in the BIC and biomechanical tests were obtained. The selected studies also showed the preferable nanotube diameter (70, 80, or 100 nm) to enhance osseointegration in BIC and/or bone area (BA). Conclusion TiO2 nanotubes, especially those with large diameters, enhanced osseointegration near titanium implants. Compared to bare nanotubes, TiO2 nanotube composite coatings resulted in higher osteogenic ability.

Small molecules including sodium butyrate (SB) and dimethyloxalylglycine (DMOG) can promote bone regeneration via inhibitive effects eliciting cellular responses through signaling cascades. The purpose of this study was to determine the synergistic effects of SB and DMOG loaded on calcium sulfate (CaS) on bone regeneration in the challenging vertical augmentation model in the rabbit calvarium. Four plastic cylinders screwed on the calvarium of each of 10 rabbits were randomly grafted with CaS, CaS/SB, CaS/DMOG, or CaS/DMOG/SB. All specimens were assessed by radiographic, histologic, and histomorphometric analyses. In the radiographic analysis, three different layers (new bone, degraded CaS, and pristine CaS layers) could be distinguished within the cylinder in all groups at 2 weeks. Newly formed bone grew up from basal bone, and CaS in contact with newly formed bone was degraded into small particles to form a different layer. At 8 weeks, most of the pristine CaS had been absorbed and hardly seen within the cylinder. In the histomorphometric analysis, all groups showed comparable new bone areas and heights at 2 and 8 weeks. The DMOG group showed a significant increase in new bone area at 8 weeks compared with 2 weeks, but there was no significant difference among the groups at 8 weeks. The DMOG group showed significantly lower values for the residual material area than the control group at 2 weeks. Within the limitations of this study, SB and DMOG seem to exert smaller synergistic effects on bone regeneration compared to CaS alone in vertical bone augmentation.

Background. The aim of this study was to assess the volumetric stability and bone formation in grafts with Bio-Oss and autogenous bone at different proportions in rabbit calvaria. Material and Methods. Ten rabbits received four titanium cylinders in their calvaria and randomly divided into the following groups: Group I: Bio-Oss (100%), Group II: Bio-Oss (75%) + autogenous bone (25%), Group III: Bio-Oss (50%) + autogenous bone (50%), and Group IV: autogenous bone (100%). After twelve weeks, the animals were euthanized, and samples were collected for clinical and histological analysis. Results. Clinical analysis showed that Groups I (90.43 ± 8.99) and II (90.87 ± 7.43) had greater dimensional stability compared to Group IV (P=0.0005). Histologically, Groups I, II, and III showed areas of bone formation with particles of biomaterial remaining in close contact with the newly formed bone. However, there were no significant differences between the groups regarding the newly formed bone area. Conclusion. It was concluded that the use of Bio-Oss either alone or associated with the autogenous bone at a proportion of 25% showed superior dimensional stability compared to the use of autogenous bone in the proposed experimental model.

Aim: The aim of this in vivo study was to evaluate the utility of bone graft gel containing hydroxyapatite nanoparticles in promoting bone regeneration in a mouse model of vertical bone augmentation. Materials and Methods: Gel implants with high and low viscosity were compared for their bone regenerating ability. Bone formation at 12 weeks and material reactions were observed radiographically and histologically. Results: Radiological analysis showed that most bone augmentation area in the graft material occurred in the fourth week after surgery regardless of the viscosity of the gel, and then gradually decreased. The volume of bone augmentation area was greater in the high-viscosity implant group than in the low-viscosity implant group at all time points, the difference was statistically significant at 8 and 12 weeks. Histological evaluation indicated that the new bone area was significantly smaller in the high-viscosity implant group. Conclusion: Gelatinous graft materials containing hydroxyapatite nanoparticles were confirmed to be useful in vertical bone augmentation.

Purpose To overcome several drawbacks of chemically-crosslinked collagen membranes, modification processes such as ultraviolet (UV) crosslinking and the addition of biphasic calcium phosphate (BCP) to collagen membranes have been introduced. This study evaluated the efficacy and biocompatibility of BCP-supplemented UV-crosslinked collagen membrane for guided bone regeneration (GBR) in a rabbit calvarial model. Methods Four circular bone defects (diameter, 8 mm) were created in the calvarium of 10 rabbits. Each defect was randomly allocated to one of the following groups: 1) the sham control group (spontaneous healing); 2) the M group (defect coverage with a BCP-supplemented UV-crosslinked collagen membrane and no graft material); 3) the BG (defects filled with BCP particles without membrane coverage); and 4) the BG+M group (defects filled with BCP particles and covered with a BCP-supplemented UV-crosslinked collagen membrane in a conventional GBR procedure). At 2 and 8 weeks, rabbits were sacrificed, and experimental defects were investigated histologically and by micro-computed tomography (micro-CT). Results In both micro-CT and histometric analyses, the BG and BG+M groups at both 2 and 8 weeks showed significantly higher new bone formation than the control group. On micro-CT, the new bone volume of the BG+M group (48.39±5.47 mm3) was larger than that of the BG group (38.71±2.24 mm3, P=0.032) at 8 weeks. Histologically, greater new bone area was observed in the BG+M group than in the BG or M groups. BCP-supplemented UV-crosslinked collagen membrane did not cause an abnormal cellular reaction and was stable until 8 weeks. Conclusions Enhanced new bone formation in GBR can be achieved by simultaneously using bone graft material and a BCP-supplemented UV-crosslinked collagen membrane, which showed high biocompatibility and resistance to degradation, making it a biocompatible alternative to chemically-crosslinked collagen membranes., Graphical Abstract

PURPOSE This study represents a systematic review of the literature to assess the effectiveness of strontium-coated titanium surfaces on osseointegration in experimental assays with healthy, nonosteoporotic and/or nonosteopenic animals. MATERIALS AND METHODS An electronic search was conducted of the databases MEDLINE/PubMed, Wiley Library, and Web of Science through 2018, with the aim of identifying studies on the osseointegration of titanium implants modified with strontium. RESULTS A total of 255 papers were found, of which 11 were included in this systematic review. The primary result was the percentage of bone-to-implant contact (BIC) around the titanium implants with or without a strontium-coated surface. The different techniques used to coat titanium surfaces with strontium recorded significant results in terms of the improvement in the implant's quality, as they increased its contact with the bone, bone area, and bone formation, as well as enhanced its biomechanical properties. CONCLUSION Nine of 11 studies reported that titanium implants coated with strontium showed significantly higher BIC (P < .001 to P < .05). This coating also improved the implants' biomechanical properties.

Objective: The aim of this study was to evaluate the effect of teriparatide (PTH 1-34, rhPTH) on a rabbit defect model with local xenogen grafts histomorphometrically and radiologically. Methods: For this purpose, two 10 mm diameter critical-size defects were created in the calvaria of 16 rabbits. In the control group, the defect area was filled with a xenogen graft, while in the teriparatide group (PTH 1-34), a xenogen graft combination with 20 mcg teriparatide was used. For both 4 – week and 8 – week study groups, new bone, residual graft, and soft tissue areas were evaluated as well as bone volume histomorphometrically and radiologically. Results: Histomorphometrically, there was a significant difference in new bone area values at the 8th week (p 0.05). There was no statistically significant difference between the groups at both 4 and 8 weeks (p > 0.05). In the radiologically measured total bone volume values, PTH1-34 group values were found to be significantly higher for both 4 – and 8 – weeks values compared to the control groups (p

Objectives The aim of this study was to assess the influence of transgingival compared with submerged healing on peri-implant bone maintenance around a novel, fully tapered implant in a healed crestal ridge in minipigs. Materials and methods In each of 12 minipigs, two implants (Straumann® BLX, Roxolid® SLActive®, Ø 3.75 × 8 mm) were placed. Implants were either left for submerged or for transgingival healing for 12 weeks. Measurements performed were bone-to-implant contact (BIC), first bone-to-implant contact (fBIC), bone area to total area (BATA), perpendicular bone crest to implant shoulder (pCIS), bone height change from placement, and bone overgrowth (for submerged implants). Results No significant differences were found between transgingival and submerged healing in any of the measured parameters, except for BATA on the buccal aspect in which significantly more bone formation was found for the transgingival healing group. For both groups, there was a gain in crestal bone height during the 12-week healing period. Conclusions Loaded compared with unloaded implants displayed comparable levels of osseointegration and equivalent marginal bone levels. This qualifies the implant placement protocol with respect to the osteotomy dimensions and subcrestal placement protocol for immediate loading. Clinical relevance The here presented results related to osseointegration and crestal bone maintenance after submerged or transgingival healing have demonstrated a high level of consistency in the used in vivo translational model. The obtained results support the translation of the novel implant type in conjunction with the developed surgical workflow and placement protocol into further clinical investigation and use.

Objective: To study the bone induction and defect repair of true bone ceramics (TBC) combined with rhBMP-2 and Sr. Methods: MC3T3-E1 cells were used to evaluate the bioactivity of the composite. Cell proliferation activity was detected by CCK-8, ALP activity was detected by p-nitrophenyl phosphate (PNPP), and the differences of material surface topography were observed by scanning electron microscopy (SEM). Bone induction was verified by the implantation in nude mice. The rabbit femoral condyle defect model was achieved to verify the bone defect repair ability of the material. Results: SEM results showed nearly the same surface morphology and cell proliferation quantified by CCK-8 showed that compared with TBC, both TBC&Sr and TBC&BMP-2&Sr had a significant promoting effect (P P

The multi-spiked connecting scaffold (MSC-Scaffold) prototype is the essential innovation in the fixation of components of resurfacing total hip arthroplasty (THRA) endoprostheses in the subchondral trabecular bone. We conducted the computed micro-tomography (micro-CT) assessment of the subchondral trabecular bone microarchitecture before and after the MSC-Scaffold embedding in femoral heads removed during long-stem endoprosthesis total hip arthroplasty (THA) of different bone densities from 4 patients with hip osteoarthritis (OA). The embedding of the MSC-Scaffold in subchondral trabecular bone causes the change in its relative area (BA/TA, bone area/total area ratio) ranged from 18.2% to 24.7% (translating to the calculated density ρB relative change 11.1–14.4%, and the compressive strength S relative change 75.3–122.7%) regardless of its initial density (before the MSC-Scaffold embedding). The densification of the trabecular microarchitecture of subchondral trabecular bone due to the MSC-Scaffold initial embedding gradually decreases with the increasing distance from the apexes of the MSC-Scaffold’s spikes while the spatial extent of this subchondral trabecular bone densification ranged from 1.5 to 2.5 mm (which is about half the height of the MSC-Scaffold’s spikes). It may be suggested, despite the limited number of examined femoral heads, that: (1) the magnitude of the effect of the MSC-Scaffold embedding on subchondral trabecular bone densification may be a factor contributing to the maintenance of the MSC-Scaffold also for decreased initial bone density values, (2) the deeper this effect of the subchondral trabecular bone densification, the better strength of subchondral trabecular bone, and as consequence, the better post-operative embedding of the MSC-Scaffold in the bone should be expected.

Objective To compare the outcome after extensive lateral guided bone regeneration using deproteinized bovine bone mineral (DBBM) with or without autogenous bone chips in a canine model of chronic horizontal alveolar ridge defect. Materials and methods The second, third and fourth lower premolars of both sides were extracted, and the buccal bone walls were completely removed in five beagle dogs. After 4 weeks, DBBM particles mixed with autogenous bone chips at a ratio of 1:1 were grafted at one side (DBBM/Auto group), while DBBM particles alone were grafted at the contralateral side (DBBM group). The graft materials on both sides were covered by a resorbable collagen membrane and fixation pins. Microcomputed tomographic volume and histomorphometric analyses were performed at 16 weeks post-surgery. Results The ridges of both groups were recovered horizontally, but new bone formation beyond the original ridge contour at the defect site was not found. The DBBM group exhibited a larger total radiographic augmented volume and new bone volume compared with the DBBM/Auto group, but the differences were minimal (p > 0.05). Histologically, the regenerated area and new bone area were also slightly larger without any statistical significance in the DBBM group than in the DBBM/Auto group (p > 0.05). Conclusion The addition of autogenous bone chips to DBBM for lateral ridge augmentation may confer no advantage over grafting DBBM alone with respect to both space maintenance and de novo bone formation in dogs.

3D printing technology has been gradually applied to various areas. In the present study, 3D-printed implants were fabricated with direct metal laser sintering technique for a dental single root with titanium. The 3D implants were allocated into following groups: not treated (3D-None), sandblasted with a large grit and acid-etched (3D-SLA), and target-ion-induced plasma-sputtered surface (3D-TIPS). Two holes were drilled in each tibia of rabbit, and the three groups of implants were randomly placed with a mallet. Rabbits were sacrificed at two, four, and twelve weeks after the surgery. Histologic and histomorphometric analyses were performed for the evaluation of mineralized bone-to-implant contact (mBIC), osteoid-to-implant contact (OIC), total bone-to-implant contact (tBIC), mineralized bone area fraction occupancy (mBAFO), osteoid area fraction occupancy (OAFO), and total bone area fraction occupancy (tBAFO) in the inner and outer areas of lattice structure. At two weeks, 3D-TIPS showed significantly higher inner and outer tBIC and inner tBAFO compared with other groups. At four weeks, 3D-TIPS showed significantly higher outer OIC than 3D-SLA, but there were no significant differences in other variables. At twelve weeks, there were no significant differences. The surface treatment with TIPS in 3D-printed implants could enhance the osseointegration process in the rabbit tibia model, meaning that earlier osseointegration could be achieved.

Distraction osteogenesis (DO) is a physiological process that generates new bone tissue formation, using progressively separated bone fragments. Recently, several techniques have been investigated to develop the maturation of the new bone tissue. Bisphosphonates was an effective material for the acceleration of bone formation in DO procedures. The purpose of this study was to evaluate the effects of the systemic zoledronic acid application at the beginning of the consolidation period on new bone genesis in a DO model of rat femurs. The rats were divided randomly into 3 groups, as follows: Control group (CNT group) (n = 10), zoledronic acid dosage-1 (n = 10), and dosage-2 (n = 10) groups (ZA-D-1 and ZA-D-2). No treatment was administered in controls, but DO was applied to the rat femurs. A single dose of 0.1 mg/kg and 0.2 mg/kg of zoledronic acid was administered systematically at the beginning of the consolidation period after the distraction in treatment groups, respectively. Histomorphometric analyses were performed on the original distracted bone area and the surrounding bone tissue. Osteoblasts, new bone formation, and fibrosis were scored. New bone formation in the ZA-D-1 and ZA-D-2 groups, when compared with the control group, was detected highly (P

We examined the effect of jump exercise on bone parameters in young female rats under food restriction. Seven-week-old female rats were divided into four groups: a sedentary and ad libitum feeding group (n = 10), a jump exercise and ad libitum feeding group (n = 9), a sedentary and 30% food restriction group (n = 9), and a jump exercise and 30% food restriction group (n = 10). The jump groups jumped 20 times/day, 5 times/week. The experiment lasted for 13 weeks. There were no interactions of jump exercise and food restriction on bone. Jump exercise under food restriction conditions induced higher bone strength, bone mineral content, bone area, bone mineral density (BMD), and cortical bone volume in young female rats, similar to rats under ad libitum feeding conditions. Bone strength parameters were not significantly different between ad libitum intake and food restriction with jump exercise training; however, BMD, bone size, and bone mass in the food restriction groups did not reach the levels of those in the ad libitum conditions group with jump exercise training. Neither jump exercise nor food restriction had a significant effect on serum estradiol or IGF-1. Our study reveals jump exercise attenuates loss of biomechanical properties and some bone sites with food restriction in young female rats.

Background Australian adolescents with low motor competence (LMC) have higher fracture rates and poorer bone health compared to European normative data, but currently no normative data exists for Australians. Aims To examine whether there were bone health differences in Australian adolescents with LMC or Developmental Coordination Disorder (DCD) when compared to typically developing age-matched Australian adolescents. Methods and Procedures Australian adolescents aged 12–18 years with LMC/DCD (n = 39; male = 27; female = 12) and an Australian comparison sample (n = 188; boys = 101; girls = 87) undertook radial and tibial peripheral Quantitative Computed Tomography (pQCT) scans. Stress Strain Index (SSI (mm3)), Total Bone Area (TBA (mm2)), Muscle Density (MuD [mgcm3]), Muscle Area (MuA [cm2]), Subcutaneous Fat Area (ScFA [cm2]), Cortical Density (CoD [mgcm3]), Cortical Area (CoD [mm2]), cortical concentric ring volumetric densities, Functional Muscle Bone Unit Index (FMBU: (SSI/bone length)) and Robustness Index (SSI/bone length^3), group and sex differences were examined. Outcome and Results The main finding was a significant sex-x-group interaction for Tibial FMBU (p = .021), Radial MuD (p = .036), and radial ScFA (p = .002). Boys with LMC/DCD had lower tibial FMBU scores, radial MuD and higher ScFA than the typically developing age-matched sample. Conclusion and Implications Comparisons of bone measures with Australian comparative data are similar to European findings however sex differences were found in the present study. Australian adolescent boys with LMC/DCD had less robust bones compared to their well-coordinated Australian peers, whereas there were no differences between groups for girls. These differences may be due to lower levels of habitual weight–bearing physical activity, which may be more distinct in adolescent boys with LMC/DCD compared to girls.

Magnesium (Mg) is an emerging degradable metal for orthopaedics and its degradation product, Mg2+, has been reported to positively affect osteogenesis. Porous hydroxyapatite (HA) has been extensively studied for bone regeneration, but its slow degradation is an important factor limiting its uses. Therefore, we studied the combination of Mg and HA to integrate the advantages of the two materials while circumventing their disadvantages, with the aim of determining the optimum Mg/HA ratio. Surface-treated Mg particles (Φ ∼ 1.3 mm) and HA spheres (Φ ∼ 1.4 mm) were mixed at 0, 10, 30, and 50% (v/v). The mixtures were filled in titanium cages to form complexes. In vitro biocompatibility was studied by culturing MC3T3-E1 osteoblasts in extracts prepared from the complexes. In vivo biocompatibility and osteoinduction were evaluated by implantation in canine dorsal muscles. All complexes were not cytotoxic to the osteoblasts, regardless of the Mg proportion. Eight weeks after implantation in muscles, complexes containing 50% Mg showed inflammatory cell infiltration, whereas all other groups showed no evident inflammatory response. Additionally, complexes containing 30% Mg had significantly higher new bone area percentage (BV/TV), trabecular number (Tb.N), and bone growth rate than those containing 0, 10%, or 50% Mg. In comparison, complexes containing 50% Mg had significantly lower BV/TV and Tb.N than all other groups, and also had a significantly lower bone growth rate than those containing 10% or 30% Mg. Sixteen weeks after implantation, the trend in bone formation was similar to that observed at week 8. This shows that metallic Mg affected the osteoinductivity of HA-Mg complexes in a dose-dependent manner. In the present model, 30% Mg induced optimum osteoinduction. More studies are needed to explore the optimum Mg fractions for other implantation sites or forms of use.

Implant placement in severely atrophic jaws is especially challenging because of the poor quality and quantity of the future implant bed. Although various bone augmentation procedure like ridge augmentation, sinus lift these procedures are possible today but it may lead to surgical morbidity they increase the risks and costs of dental implant treatment as well as the number of necessary operations. Also sometimes the patient is not agreeing for such extensive surgical procedures, according to the well-known implantological rules for dental restorations, crestal implants are indicated in situations when an adequate vertical bone supply is given but single piece dental implant (basal implants) is a viable treatment option derives support from the basal bone area which usually remains free from the infection and less prone to resorption.

This study aimed to investigate implant osseointegration using a new strategy of biphasic calcium phosphate (BCP) bone substitutes with simultaneous implant placement in mandibular reconstruction. Additionally, the temporal transcriptional profile associated with the early biological processes during osseointegration was determined. BCP and hydroxyapatite (HA) bone substitutes with simultaneous implant placement were grafted into mandibular defects created in mini-swine. Radiographic, histological, and biochemical analyses were applied for evaluation of osseointegration effects at 4 months after the grafting procedure. Bone formation around the implant was assessed by the bone area percentage (BA%) and the bone-implant-contact percentage (BIC%). The biomechanical evaluation was performed by the implant pullout test and the removal torque test. Microarray technology was utilized for gene expression comparison analysis at day 14 postoperatively. Radiographic and histological observation indicated enhanced bone formation in the BCP group compared to the HA group. Histomorphometric analyses of BA% and BIC% as well as biochemical analyses of the maximal pull-out force and the ultimate shear strength were all significantly greater in the BCP group (p < 0.05). Transcriptional analysis at an early stage of osseointegration revealed that genes belonging to biological processes associated with cell proliferation, development, osteogenesis, angiogenesis, and neurogenesis as well as the osteogenesis-related TGF-β/BMP and WNT signaling pathways were upregulated in the BCP group. In conclusion, the reconstruction of mandibular defects using BCP with simultaneous implant placement resulted in superior osseointegration effects. A number of candidate genes that were differentially expressed may contribute to the superior osseointegration effects. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2071-2079, 2019.

Background: Osteoarthritis is one of the chronic debilitating disease affecting the temporomandibular joint (TMJ). Even though there are several therapeutic approaches to treat osteoarthritic joints, intra-articular injection provides local drug delivery to the joint with instant pain relief. Purpose: The aim of this study was to investigate the regenerative potential of intraarticular injections of Platelet-Rich Plasma (PRP), Botox and Botox + PRP (combined) in treating induced temporomandibular joint (TMJ) osteoarthritis in Albino rats.Design: 42 male adult Wister albino rats were used in this study. All rats were anesthetized and injected with 2mg MIA in both sides of TMJ to induce osteoarthritis. After confirmation of osteoarthritis by enzyme-linked immunosorbent assay (ELISA), the rats were randomly divided to three groups. The right side acted as the experimentally treated group and was injected weekly with either Botox (5 IU/kg diluted in 50 µL saline), 50 µL PRP, or their combination, while the left side acted as control. Tissues were assessed at two and four weeks post-treatment histologically, radiographically and biochemically (using qRT-PCR and ELISA).Results: The treated sides showed statistically significantly higher mean bone area percentages, in addition to lower statistically significantly mean IL-1β and MMP13 levels than the untreated sides. The highest mean bone area % was recorded in the PRP group followed by the combined group of Botox+ PRP. The treated sides recorded a higher mean joint space than the untreated sides that is statistically significant in the Botox group (p < 0.001) and statistically non-significant in the PRP and Botox+ PRP group. Conclusion: This study confirms the regenerative potential of PRP alone and in combination with Botox, which implies that the use of PRP alone or combined with Botox can enhance the healing of conditions as TMJ osteoarthritis.