Socket shield technique: A systemic review and meta-analysis.

PURPOSE: The aim of the present study was to evaluate the clinical feasibility of the socket shield technique (SST). STUDY SELECTION: An electronic search of the PubMed, Cochrane Central Register of Controlled Trials, and Wiley Online Library databases, and a manual reference search for articles published up to September 2020 was conducted. Meta-analysis was performed to estimate marginal bone loss (MBL), changes in buccal bone width (cBBW), pink esthetic score (PES), implant stability quotient (ISQ), implant failure rate, and complication rate between SST and conventional immediate implant placement (IIP). All pooled analyses were based on random effects models. RESULTS: Sixteen relevant studies were ultimately selected by two independent reviewers: four randomized clinical trials (RCTs), four case-control studies, and eight retrospective studies. Meta-analysis revealed a trend toward lower MBL and cBBW and higher PES in the SST group. ISQ, implant failure rate, and complication rate were similar between the groups. CONCLUSION: The included studies provided evidence that SST may be a feasible treatment option. However, this technique should not be used as a routine clinical protocol due to the lack of evidence-based consensus guidelines, large-scale RCTs, and long-term follow-up data. Therefore, there is an urgent need for well-conducted RCTs in this field.

Polypeptides IGF-1C and P24 synergistically promote osteogenic differentiation of bone marrow mesenchymal stem cells in vitro through the p38 and JNK signaling pathways.

OBJECTIVES: Insulin-like growth factor-1 (IGF-1) and bone morphogenetic protein 2 (BMP-2) both promote osteogenesis of bone marrow mesenchymal stem cells (BMSCs). IGF-1C, the C domain peptide of IGF-1, and P24, a BMP-2-derived peptide, both have similar biological activities as their parent growth factors. This study aimed to investigate the effects and mechanisms of polypeptides IGF-1C and P24 on the osteogenic differentiation of BMSCs. METHODS: The optimum concentrations of IGF-IC and P24 were explored. The effects of the two polypeptides on BMSC proliferation and osteogenic differentiation were examined using a CCK-8 assay, flow cytometry, alkaline phosphatase (ALP) staining, ALP activity assay, alizarin red S staining, qPCR, and Western blotting. In addition, specific pathway inhibitors were utilized to explore whether the p38 and JNK pathways were involved in this process. RESULTS: The optimal concentration of both polypeptides was 50 µg/ml. IGF-1C and P24 synergistically promoted BMSC proliferation, increased ALP activity and calcified nodule formation, upregulated the mRNA and protein levels of Osx, Runx2, Ocn, Opn, and Col1a1, and improved the phosphorylation levels of p38 and JNK proteins. Inhibition of the pathways significantly reduced p38 and JNK activation and blocked Runx2 expression while inhibiting ALP activity and calcified nodule formation. CONCLUSIONS: These findings suggest that IGF-1C and P24 synergistically promote the osteogenesis of BMSCs through activation of the p38 and JNK signaling pathways.

Retraction of "Biological Effects of Titanium Surface Charge with a Focus on Protein Adsorption".

[This retracts the article DOI: 10.1021/acsomega.0c02518.].

Application of the socket shield technique and its potential risks / 口腔疾病防治

@#The rapid absorption of labial alveolar bone after tooth extraction not only reduces the aesthetic effect of implant repair but also affects the long-term success rate of implants. The socket shield technique is reported as the latest alveolar preservation technique in the aesthetic zone from both domestic and international case reports and shows a high success rate of short-term osseointegration and excellent aesthetic effects. However, some investigations have shown short- and long-term complications with the socket shield technique, such as failure of osseointegration, loss of crestal bone and buccal bone, inflammation, etc. In this review, the socket shield technique will be reported in detail with its pros and cons. Although the socket shield technique has achieved good clinical effects and short-term success rates in many cases, there are still no conclusions regarding the surgical procedure, such as the thickness, the position of the shield, whether to put the graft material between the shield and implant, etc. Due to the lack of long-term research or a large amount of clinical literature support and technical sensitivity, the socket shield technique should be carefully used in clinical application to reduce unexpected risks.

The Cleaning Effect of the Photocatalysis of TiO2-Bï¼ anatase Nanowires on Biological Activity on a Titanium Surface.

BACKGROUND: Improvements in the early osseointegration of titanium implants require investigations on the bone-implant interface, which is a critical and complex challenge. The surface cleanliness of titanium implants plays an important role at this interface. However, the implant surface would inevitably absorb contamination such as organic hydrocarbons, which is not conductive to the establishment of early osseointegration. Herein, an optimized approach for removing contamination from titanium surfaces was studied. METHODS: The TiO2-Bï¼ anatase NWs (nanowires) were prepared on titanium substrates through a hydrothermal process. A methylene blue degradation experiment was performed to assess the photodegradation activity. The cleaning effect of the photocatalysis of TiO2-Bï¼ anatase NWs on a titanium surface and the cellular early response was determined by analyzing cell morphology, attachment, proliferation and differentiation. RESULTS: The results indicated that the photocatalysis of TiO2-Bï¼ anatase NWs could effectively remove hydrocarbons on titanium surfaces without sacrificing the favourable titanium surface morphology. The methylene blue degradation experiment revealed that the photocatalysis of TiO2-Bï¼ anatase NWs had powerful degradation activity, which is attributed to the presence of strong oxidants such as ·OH. In addition, compared to the merely ultraviolet-treated titanium surfaces, the titanium surfaces treated after the NWs photocatalytic cleaning process markedly enhanced cellular early response. CONCLUSION: The photocatalysis of TiO2-Bï¼ anatase NWs for the removal of contamination from titanium surfaces has the potential to enable the rapid and complete establishment of early osseointegration.

Biological Effects of Titanium Surface Charge with a Focus on Protein Adsorption.

The effect of changes in surface charge on the biological properties of implants is not clear. The objective of this study was to evaluate the biological properties of the surface of titanium sheets with different charges due to different treatment methods. Titanium sheets were sandblasted with large grit and underwent acid etching before being subsequently divided into the following groups: SLA, no further treatment; SLA-Ca2+, immersed in 1% CaCl2 solution; SLA-NaCl, immersed in saline; and SLA-Ca2+-NaCl, immersed in 1% CaCl2 solution followed by saline. Surface characteristics were evaluated using field-emission scanning electron microscopy with energy-dispersive spectrometry, surface profilometry, and contact angle assays. Additionally, we used a ζ-potential analyzer to directly measure the electrostatic charge on the different group surfaces. The effect of changes in the Ti surface on biological processes after different treatments was determined by analyzing fibronectin adsorption, osteoblast-like MG63 cell adhesion and proliferation, and the expression of osteogenesis-related genes. Compared to the SLA surface, the other three groups contained corresponding trace elements because they were soaked in different liquids; the contact angles of the three groups were not significantly different, but they were significantly smaller than that of the SLA group; and there was no change in the surface topography or roughness. Furthermore, the SLA-Ca2+ group had a significantly reduced negative charge compared to that of the other three groups. There were no differences between the SLA-NaCl and SLA-Ca2+-NaCl groups in terms of negative charge, and the SLA group surface carried the most negative charge. Fibronectin adsorption capacity and cytological performance testing further showed that the SLA-Ca2+ group had the most significant change, followed by the SLA-NaCl and SLA-Ca2+-NaCl groups; the SLA group had significantly lower capacity and performance than the other three groups. These results suggest that the surface charge of the titanium sheet changed when immersed in different liquids and that this treatment enhanced biocompatibility by reducing the electrostatic repulsion between biomaterials and biomolecules.

Split-crest technique with inlay bone block grafts for narrow posterior mandibles: a retrospective clinical study with a 3-year follow-up.

The use of the split-crest technique (SCT) and bone block grafts provides benefits to horizontal bone augmentation. However, no information is currently available to evaluate the clinical effects of SCT combined with inlay bone block grafts on soft and hard tissues of the narrow posterior mandibles. In this study, 56 healthy patients underwent SCT to augment the alveolar ridge width. Implant placement was performed 3 months after SCT, and the implants were restored 3 months after placement. A planned follow-up was performed to analyze various clinical features, including X-ray radiographs, alveolar ridge width, and keratinized mucosal width, after SCT to evaluate the success of the procedure. The incisions healed well in all patients. The average initial alveolar ridge width was 2.78 ± 0.56 mm, which increased to 6.67 ± 0.60 mm after SCT. Three months later, this width declined slightly to 6.19 ± 0.48 mm. The average initial keratinized mucosal width was 2.83 ± 0.66 mm, which increased to 6.00 ± 0.71 mm 3 months later. Both at 3 months and 1 year after the procedure, vertical bone loss at the buccal sites was 1.32 ± 0.56 mm and 1.94 ± 0.54 mm, respectively. Survival rates of the implants were 100% after 3 years. SCT with inlay bone block grafts was successfully applied to narrow posterior mandibles with efficient augmentation of soft and hard tissue widths. The findings of this study aim to identify future beneficial applications of SCT.

Effect of laser-etched pure titanium surface on early proliferation of MG63 cells / 口腔疾病防治

Objective @# To investigate the effect of a laser-etched pure titanium surface on proliferation of the human osteosarcoma cell line MG63 and to provide a basis for study of implant surface modification. @*Methods@#The pure titanium plate was cut into titanium pieces by a numerical control machine tool and divided into smooth surface and laser etching groups. The titanium surface of the laser etching group was etched with an Nd:YAG continuous wave laser using predetermined parameters, and the surfaces were observed by scanning electron microscopy (SEM). The surface micromorphology of each titanium sheet was evaluated. The relative element content of the titanium surface was measured by energy dispersive X-ray spectroscopy (EDS). The Ra value of each surface was determined using the Veeco roughness tester. MG63 cells were inoculated on 2 sets of titanium tablets. At 1, 3, and 6 h postinoculation, cell adhesion to the two groups of titanium sheets was observed under the microscope. At 24 h after inoculation, cellular F-actin was directly stained using immunofluorescence, and the morphology of the cytoskeleton was observed by laser confocal microscopy. Cell proliferation was examined at 1, 3, and 5 d using a MTS kit, and the data were analyzed with SAS 9.4.@* Results @#The surface of the smooth surface group was smooth and flat, the element composition was pure titanium, and the roughness Ra was 179.23 nm. The surface of the laser-etched group formed a regular and uniform pore structure. The composition was mainly Ti, O, C, etc, and the surface roughness Ra was 14.11 μm. A large number of cells were uniformly distributed on the two titanium sheets in the observations at 1, 3, and 6 h. At 24 h postinoculation, MG63 cells were completely stretched on the two sets of titanium sheets and had extended a large number of pseudopods and microfilaments to cross-link with peripheral cells; moreover, the cell division phase was observed. The cell proliferation of the two groups at 1, 3, and 5 d showed a significant increase with time, indicating that no cytotoxicity occurred on the surfaces of the two groups. However, the cell proliferation in the laser-etched group was superior to that in the mechanical smooth surface group.@*Conclusion@#The surface morphology of titanium can be controlled by laser etching, which is conductive to increase the microstructure of implants without cytotoxicity and promoting osteoblast proliferation in the early stage.

Clinical observation of alveolar ridge approach for odontogenic maxillary sinusitis and implant restoration / 口腔疾病防治

Objective @# To explore the clinical effect of the alveolar crest approach in the treatment of odontogenic maxillary sinusitis and the repair of edentulous implants in this area.@*Methods@#This was a retrospective case series of 20 patients with odontogenic sinusitis. The pathogenesis in each case was investigated. After elimination of the dental origin, each patient was treated with flushing, drainage and anti-inflammatories through the alveolar crest approach. Postoperative CBCT reexamination was performed to evaluate the therapeutic effect. Maxillary sinus elevation surgery with simultaneous or delayed implantation was performed after maxillary sinusitis healing was confirmed. The patients were followed postoperatively.@*Results @#Twenty patients with odontogenic sinusitis were treated by the alveolar crest approach, and 17 were cured, for a cure rate of 85%. Among them, 17 of the maxillary sinusitis patients were followed for 1 year, with good results.@*Conclusion @#The alveolar crest approach is feasible for the treatment of odontogenic maxillary sinusitis and can serve as a minimally invasive method for the repair of edentulism in this area and implantation.

Effects of RGD-grafted TiO2 nanotubes on the adhesion and proliferation of MG63 osteoblasts / 口腔疾病防治

Objective@#To investigate the effect of pure titanium surface of large diameter TiO2 nanotubes modified by RGD peptide on the adhesion and proliferation of MG63 osteoblasts. to provide theoretical proof for developing titanium implants.@*Methods@#Commercially pure titanium discs were divided into four groups and treated with SLA to obtain a microrough surface (SLA group). Then, nanotubes were imposed on this microrough surface by anodization (SLA+80 group). The surface was then modified by dopamine (DOPA) (DOPA Group), after which bioactive RGD peptide layers were generated on the TiO2 nanotube surfaces via electrochemical and molecular self-assembly techniques (RGD group). The titanium surface morphology and elemental composition of each group were characterized by field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS). MG63 cells were cultured in vitro to evaluate biological activities of titanium before and after treatment, including the evaluation of early-stage cell adhesion capacity by fluorescence microscopy, proliferation capacity by MTS assay, and mRNA expression of the cell osteoblast-related genes alkaline phosphatase (ALP) and osteocalcin (OCN) by qRT-PCR.@*Results@#FE-SEM and XPS showed that hierarchical micro/nanosurfaces decorated with TiO2 nanotubes were produced on titanium using sandblasting and large grit etching combined with anodization, dopamine was then self-polymerized to form a polydopamine film on the TiO2 nanotube surfaces, and RGD peptides were then conjugated to the polydopamine film, finally forming RGD peptide-modified bioactive layers. In vitro experiments showed that compared with the other three materials, the RGD-modified material was more conducive to cell adhesion and proliferation (P < 0.05). The expression levels of ALP and OCN mRNA in the RGD group were significantly higher than those in the SLA group and DOPA group (P < 0.05).@*Conclusion@#Hierarchical micro/nanosurfaces decorated with TiO2 nanotubes functionally modified with RGD peptides have good biocompatibility and could be used for developing titanium implants and further improving early osseointegration.

The effects of hierarchical micro/nanosurfaces decorated with TiO2 nanotubes on the bioactivity of titanium implants in vitro and in vivo.

In the present work, a hierarchical hybrid micro/nanostructured titanium surface was obtained by sandblasting with large grit and acid etching (SLA), and nanotubes of different diameters (30 nm, 50 nm, and 80 nm) were superimposed by anodization. The effect of each SLA-treated surface decorated with nanotubes (SLA + 30 nm, SLA + 50 nm, and SLA + 80 nm) on osteogenesis was studied in vitro and in vivo. The human MG63 osteosarcoma cell line was used for cytocompatibility evaluation, which showed that cell adhesion and proliferation were dramatically enhanced on SLA + 30 nm. In comparison with cells grown on the other tested surfaces, those grown on SLA + 80 nm showed an enhanced expression of osteogenesis-related genes. Cell spread was also enhanced on SLA + 80 nm. A canine model was used for in vivo evaluation of bone bonding. Histological examination demonstrated that new bone was formed more rapidly on SLA-treated surfaces with nanotubes (especially SLA + 80 nm) than on those without nanotubes. All of these results indicate that SLA + 80 nm is favorable for promoting the activity of osteoblasts and early bone bonding.

Biological Effect of Ultraviolet Photocatalysis on Nanoscale Titanium with a Focus on Physicochemical Mechanism.

Physicochemical properties, regulated by various surface modifications, influence the biological performance of materials. The interaction between surface charge and biomolecules is key to understanding the mechanism of surface-tissue integration. The objective of this study was to evaluate the biological response to a nanoscale titanium surface after ultraviolet (UVC, λ = 250 ± 20 nm) irradiation and to analyze the effects via a physicochemical mechanism. The surface characteristics were evaluated by field-emission scanning electron microscopy, X-ray photoelectron spectroscopy, surface profilometry, and contact angle assay. In addition, we applied the zeta-potential, a direct method to measure the electrostatic charge on UV-treated and UV-untreated titanium nanotube surfaces. The effect of the Ti surface after UV treatment on the biological process was determined by analyzing bovine serum albumin (BSA) adsorption and osteoblast-like MG-63 early adhesion, morphology, cytoskeletal arrangement, proliferation, and focal adhesion. Compared to an anodized titanium nanotube coating, UV irradiation altered the contact angles on the control surface from 51.5° to 6.2° without changing the surface topography or roughness. Furthermore, titanium nanotubes after UV treatment showed a significant reduction in the content of acidic hydroxyl groups and held less negative charge than the anodized coating. With regard to the biological response, along with an enhanced capability to adsorb BSA, osteoblasts exhibited higher colonization and viability on the UV-treated material. The results suggest that UV treatment enhances the biocompatibility by reducing the electrostatic repulsion between biomaterials and biomolecules.

Phosphoric acid and sodium fluoride: a novel etching combination on titanium.

We investigate whether a novel and inexpensive etching method, H3PO4 + NaF, on titanium could obtain both a lower hydrogen content and superior calcium phosphate deposition performance, while achieving similar surface roughness in comparison with the traditional etching method. Pure titanium samples were treated with different concentrations of H3PO4 + NaF at ambient temperature without auxiliary implementations (groups A, B and C), and were treated using the traditional method (group T). The samples were then maintained in simulated body fluid for 10 and 20 days. The surface morphology and chemistry, as well as the hydrogen content and distribution, were studied. The hydrogen content of the new groups are in the range of 31 (3.6)-86.9 (7.2) ppm, and that of group T is 287 (13.5) ppm. The amount of deposited calcium phosphates increases as the hydrogen content approaches 90 ppm; however, this trend does not apply as the hydrogen content exceeds 90 ppm. The surface roughnesses of groups A, B and C are in the range of 0.47 (0.01)-0.92 (0.05) µm. The new surface topography regularly transforms, and the surfaces with round pits exert a better effect on the deposition of calcium phosphates than the surfaces with sharp cusps.

Behavior of acid etching on titanium: topography, hydrophility and hydrogen concentration.

Since acid etching is easily controlled and effective, it has become one of the most common methods of surface modification. However, the behavior of etching is seldom discussed. In this study, different surfaces of titanium were prepared by changing the etching temperature and time. Surface topography, roughness, contact angles, surface crystalline structure, hydrogen concentration and mechanical properties were observed. As a result, surface topography and roughness were more proportional to etching temperature; however, diffusion of hydrogen and tensile strength are more time-related to titanium hydride formation on the surface. Titanium becomes more hydrophilic after etching even though the micropits were not formed after etching. More and deeper cracks were found on the specimens with more hydrogen diffusion. Therefore, higher temperature and shorter time are an effective way to get a uniform surface and decrease the diffusion of hydrogen to prevent hydrogen embrittlement.

The effects of different wavelength UV photofunctionalization on micro-arc oxidized titanium.

Many challenges exist in improving early osseointegration, one of the most critical factors in the long-term clinical success of dental implants. Recently, ultraviolet (UV) light-mediated photofunctionalization of titanium as a new potential surface treatment has aroused great interest. This study examines the bioactivity of titanium surfaces treated with UV light of different wavelengths and the underlying associated mechanism. Micro-arc oxidation (MAO) titanium samples were pretreated with UVA light (peak wavelength of 360 nm) or UVC light (peak wavelength of 250 nm) for up to 24 h. UVC treatment promoted the attachment, spread, proliferation and differentiation of MG-63 osteoblast-like cells on the titanium surface, as well as the capacity for apatite formation in simulated body fluid (SBF). These biological influences were not observed after UVA treatment, apart from a weaker effect on apatite formation. The enhanced bioactivity was substantially correlated with the amount of Ti-OH groups, which play an important role in improving the hydrophilicity, along with the removal of hydrocarbons on the titanium surface. Our results showed that both UVA and UVC irradiation altered the chemical properties of the titanium surface without sacrificing its excellent physical characteristics, suggesting that this technology has extensive potential applications and merits further investigation.

Titanate nanowire scaffolds decorated with anatase nanocrystals show good protein adsorption and low cell adhesion capacity.

BACKGROUND AND METHODS: In this report, layered microporous titanate nanowire scaffolds (TiNWs) were constructed via a hydrothermal route and then decorated with anatase nanocrystals (ANs@TiNWs) by immersion in TiCl(4) solution. The diameter and specific surface area of the ANs@TiNWs was measured. The TiNWs and ANs@TiNWs were then compared for their ability to adsorb protein and adhere to MG63 cells. RESULTS: The diameter and specific surface area of the ANs@TiNWs were significantly larger than for TiNWs, and the ANs@TiNWs had an enhanced protein-adsorbing effect. It was found that the MG63 cells were less able to adhere to the flat titanium substrate than the TiNWs and ANs@TiNWs, and that this cell-repellant ability was greater with ANs@TiNWs. Other MG63 cell functions, proliferation in particular, were also inhibited by ANs@TiNWs. CONCLUSION: ANs@TiNWs show a high protein adsorption and cell-repellant capacity which would be useful in drug delivery.

[Isolation and identification of stem cells derived from human exfoliated deciduous teeth by magnetic activated cell sorting].

OBJECTIVE: To isolate stem cells from human exfoliated deciduous teeth (SHEDs) and identify their phenotypes and multi-lineage differentiation potential. METHODS: Human pulp tissue from exfoliated deciduous teeth were dissected and digested to obtain the single cell suspension. The SHEDs selected by magnetic activated cell sorting system (MACS) were identified by examination of the cell morphology and growth in vitro and detection of the expressions of the cell markers. Osteogenic and adipogenic induction was performed to test the multi-lineage differentiation potential of the cells. RESULTS: SHEDs were successfully isolated from human exfoliated deciduous teeth. SHEDs showed a lower growth rate than dental pulp cells and displayed high expressions of CD29 and CD105 but low expressions of CD34 and CD45 as shown by flow cytometry. Experiments of in vitro induction demonstrated a strong potential of the STRO-1+ SHEDs for osteogenic and adipogenic differentiation. CONCLUSION: Immunomagnetic bead selection can be used to isolate and purify SHEDs, and the STRO-1+ SHEDs show the characteristics of stem cells with multipotent differentiation potentials.