Reconstruction of mandibular bone defects using biphasic calcium phosphate bone substitutes with simultaneous implant placement in mini‐swine: A pilotin vivostudy

Abstract

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.

Biomaterial Properties Modulating Bone Regeneration

“…Biomaterials commonly investigated in bone regeneration can be classified based on their source of origin, mainly natural and synthetic biomaterials ( Table 1 ). [ 22 ] Naturally occurring biomaterials include inorganic ceramics such as calcium phosphates [ 23–26 ] and hydroxyapatite (HA). [ 27–29 ] Organic polymers consist of proteins such as: collagen, [ 30–32 ] gelatin, [ 33 ] elastin, [ 34 ] silk, [ 35 ] fibrin, [ 36,37 ] and keratin.…”

Wnt signalling in oral and maxillofacial diseases

“…In recent years, some studies have shown that the Wnt/β‐catenin signalling pathway mediates the osteogenesis of osteogenic lineage cells on the surface of many kinds of implants, which can enhance osseointegration. An early transcription analysis of osseointegration showed that osteogenesis‐related TGF‐β/BMP and Wnt signalling pathways were upregulated in the treatment group that used biphasic calcium phosphate (BCP) as bone substitute materials (Z. Zhang et al, 2019). Huang et al (2019) combined lithium with sandblasting, large‐grit and acid‐etching (SLA) of titanium implants through hydrothermal treatment and found that the implants could activate the Wnt/β‐catenin signalling pathway to promote bone formation and inhibit osteoclasts.…”

Melatonin and calcium phosphate crystal-loaded poly(l-lactic acid) porous microspheres reprogram macrophages to improve bone repair

“…Consequently, it is widely applied in the fields of bone defect repair and bone tissue regeneration. 16 Melatonin is a hormone secreted by the pineal gland in humans that regulates the sleep-wake cycle, inhibits tumor growth, acts as an antioxidant, and modulates the immune system. 17 Melatonin receptors have two subtypes, MT1 and MT2, which belong to the G protein-coupled receptor family.…”

“…Consequently, it is widely applied in the fields of bone defect repair and bone tissue regeneration. 16…”