Giuseppe Intini

Background: The aim of this systematic review and meta‐analysis was to compare the clinical efficacy of the early dental implant placement protocol with immediate and delayed dental implant placement protocols.Methods: An electronic and manual search of literature was made to identify clinical studies comparing early implant placement with immediate or delayed placement. Data from the included studies were pooled and quantitative analyses were performed for the implant outcomes reported as the number of failed implants (primary outcome variable) and for changes in peri‐implant marginal bone level, peri‐implant probing depth, and peri‐implant soft tissue level (secondary outcome variables).Results: Twelve studies met the inclusion criteria. Significant difference in risk of implant failure was found neither between the early and immediate placement protocols (risk difference = −0.018; 95% confidence interval [CI] = −0.06, 0.025; P = 0.416) nor between early and delayed placement protocols (risk difference = −0.008; 95% CI = –0.044, 0.028; P = 0.670). Pooled data of changes in peri‐implant marginal bone level demonstrated significantly less marginal bone loss for implants placed using the early placement protocol compared with those placed in fresh extraction sockets (P = 0.001; weighted mean difference = −0.14 mm; 95% CI = −0.22, −0.05). No significant differences were found between the protocols for the other variables.Conclusions: The available evidence supports the clinical efficacy of the early implant placement protocol. Present findings indicate that the early implant placement protocol results in implant outcomes similar to immediate and delayed placement protocols and a superior stability of peri‐implant hard tissue compared with immediate implant placement.

Histomorphometry and Micro-CT are commonly used to assess bone remodeling and bone microarchitecture. These approaches typically require separate cohorts of animals to analyze 3D morphological changes and involve time-consuming immunohistochemistry preparation. Intravital Microscopy (IVM) in combination with mouse genetics may represent an attractive option to obtain bone architectural measurements while performing longitudinal monitoring of dynamic cellular processesin vivo. In this study we utilized two-photon, multicolor fluorescence IVM together with a lineage tracing reporter mouse model to image skeletal stem cells (SSCs) in their calvarial suture niche and analyze their differentiation fate after stimulation with an agonist of the canonical Wnt pathway (recombinant Wnt3a). Ourin vivohistomorphometry analyses of bone formation, suture volume, and cellular dynamics showed that recombinant Wnt3a induces new bone formation, differentiation and incorporation of SSCs progeny into newly forming bone. IVM technology can therefore provide additional dynamic 3D information to the traditional static 2D histomorphometry.

Periodontal diseases are highly prevalent and are linked to several systemic diseases. The goal of periodontal treatment is to halt the progression of the disease and regenerate the damaged tissue. However, achieving complete and functional periodontal regeneration is challenging because the periodontium is a complex apparatus composed of different tissues, including bone, cementum, and periodontal ligament. Stem cells may represent an effective therapeutic tool for periodontal regeneration due to their plasticity and their ability to regenerate different tissues. This review presents and critically analyzes the available information on stem cell‐based therapy for the regeneration of periodontal tissues and suggests new avenues for the development of more effective therapeutic protocols. J. Cell. Physiol. 230: 50–61, 2016.

Femtosecond laser pulses can be used to perform very precise cutting of material, including biological samples from subcellular organelles to large areas of bone, through plasma-mediated ablation. The use of a kilohertz regenerative amplifier is usually needed to obtain the pulse energy required for ablation. This work investigates a 5 megahertz compact fiber laser for near-video rate imaging and ablation in bone. After optimization of ablation efficiency and reduction in autofluorescence, the system is demonstrated for the in vivo study of bone regeneration. Image-guided creation of a bone defect and longitudinal evaluation of cellular injury response in the defect provides insight into the bone regeneration process.

This article reviews recent research into mechanisms underlying bone resorption and highlights avenues of investigation that may generate new therapies to combat alveolar bone loss in periodontitis. Several proteins, signaling pathways, stem cells, and dietary supplements are discussed as they relate to peri-odontal bone loss and regeneration. RGS12 is a crucial protein that mediates osteoclastogenesis and bone destruction, and a potential therapeutic target. RGS12 likely regulates osteoclast differentiation through regulating calcium influx to control the calcium oscillation-NFATc1 pathway. A working model for RGS10 and RGS12 in the regulation of Ca2+ oscillations during osteoclast differentiation is proposed. Initiation of inflammation depends on host cell-microbe interactions, including the p38 mitogen-activated protein kinase (MAPK) signaling pathway. Oral p38 inhibitors reduced lipopolysaccharide (LPS)-induced bone destruction in a rat periodontitis model but showed unsatisfactory safety profiles. The p38 substrate MK2 is a more specific therapeutic target with potentially superior tolerability. Furthermore, MKP-1 shows anti-inflammatory activity, reducing inflammatory cytokine biosynthesis and bone resorption. Multipotent skeletal stem cell (SSC) populations exist within the bone marrow and periosteum of long bones. These bone-marrow-derived SSCs and periosteum-derived SSCs have shown therapeutic potential in several applications, including bone and periodontal regeneration. The existence of craniofacial bone-specific SSCs is suggested based on existing studies. The effects of calcium, vitamin D, and soy isoflavone supplementation on alveolar and skeletal bone loss in post-menopausal women were investigated. Supplementation resulted in stabilization of forearm bone mass density and a reduced rate of alveolar bone loss over 1 yr, compared with placebo. Periodontal attachment levels were also well-maintained and alveolar bone loss suppressed during 24 wk of supplementation.

The bone-regenerative potentials of the periosteum have been explored as early as the 17th century. Over the past few years, however, much has been discovered in terms of the molecular and cellular mechanisms that control the periosteal contribution to bone regeneration. Lineage tracing analyses and knock-in transgenic mice have helped define the relative contributions of the periosteum and endosteum to bone regeneration. Additional studies have shed light on the critical roles that BMP, FGF, Hedgehog, Notch, PDGF, Wnt, and inflammation signaling have or may have in periosteal-mediated bone regeneration, fostering the path to novel approaches in bone-regenerative therapy. Thus, by examining the role that each pathway has in periosteal-mediated bone regeneration, in this review we analyze the status of the current research on the regenerative potential of the periosteum. The provided analysis aims to inform both clinician-scientists who may have interest in the current studies about the biology of the periosteum as well as dental surgeons who may find this review useful to perform periosteal-harnessing bone-regenerative procedures.

Background: Piezosurgery is an osteotomy system used in medical and dental surgery. Manystudies have proven clinical advantages of piezosurgery in terms of quality ofcut, maneuverability, ease of use, and safety. However, few investigations havetested its superiority over the traditional osteotomy systems in terms of dynamicsof bone healing. Therefore, the aim of this study was to evaluate the dynamics ofbone healing after osteotomies with piezosurgery and to compare them with thoseassociated to traditional bone drilling. Methods: One hundred and ten rats were divided into two groups with 55 animals each. Theanimals were anesthetized and the tibiae were surgically exposed to create defects2 mm in diameter by using piezosurgery (Piezo group) and conventionaldrilling (Drill group). Animals were sacrificed at 3, 7, 14, 30 and 60 dayspost-surgery. Bone samples were collected and processed for histological,histomorphometrical, immunohistochemical, and molecular analysis. The histologicalanalysis was performed at all time points (n = 8) whereas thehistomorphometrical analysis was performed at 7, 14, 30 and 60 dayspost-surgery (n = 8). The immunolabeling was performed to detectVascular Endothelial Growth Factor (VEGF), Caspase-3 (CAS-3), Osteoprotegerin(OPG), Receptor Activator of Nuclear Factor kappa-B Ligand (RANKL), andOsteocalcin (OC) at 3, 7, and 14 days (n = 3). For the molecularanalysis, animals were sacrificed at 3, 7 and 14 days, total RNA wascollected, and quantification of the expression of 21 genes related to BMPsignaling, Wnt signaling, inflammation, osteogenenic and apoptotic pathways wasperformed by qRT-PCR (n = 5). Results: Histologically and histomorphometrically, bone healing was similar in both groupswith the exception of a slightly higher amount of newly formed bone observed at30 days after piezosurgery (p < 0.05). Immunohistochemical andqRT-PCR analyses didn’t detect significant differences in expression of allthe proteins and most of the genes tested. Conclusions: Based on the results of our study we conclude that in a rat tibial bone defectmodel the bone healing dynamics after piezosurgery are comparable to thoseobserved with conventional drilling.