Thy-1 knockdown promotes the osteogenic differentiation of GMSCs via the Wnt/ß-catenin pathway.

Gingival mesenchymal stem cells (GMSCs) are newly developed seed cells for tissue engineering owing to their easy isolation, abundance and high growth rates. Thy-1 is an important regulatory molecule in the differentiation of mesenchymal stem cells (MSCs). In this study, we investigated the function of Thy-1 in the osteogenic differentiation of GMSCs by reducing the expression of Thy-1 using a lentivirus. The results demonstrated that Thy-1 knockdown promoted the osteogenic differentiation of GMSCs in vitro. Validation by RNA-seq revealed an obvious decrease in Vcam1 and Sox9 gene expression with Thy-1 knockdown. Kyoto Encyclopedia of Genes and Genomes pathway analysis suggested that the differentially expressed genes were enriched in the Wnt signalling pathway. We further demonstrated that Thy-1 knockdown promoted osteogenic differentiation of GMSCs by activating the Wnt/ß-catenin signalling pathway. Therefore, Thy-1 has a key regulatory role in the differentiation of GMSCs and maybe a core molecule connecting transcription factors related to the differentiation of MSCs. Our study also highlighted the potential of Thy-1 to modify MSCs, which may help improve their use in tissue engineering.

Does the incorporation of strontium into calcium phosphate improve bone repair? A meta-analysis.

BACKGROUND: The application of calcium phosphate (CaP)-based bone substitutes plays an important role in periodontal regeneration, implant dentistry and alveolar bone reconstruction. The incorporation of strontium (Sr) into CaP-based bone substitutes appears to improve their biological properties, but the reported in vivo bone repair performance is inconsistent among studies. Herein, we conducted a systematic review and meta-analysis to investigate the in vivo performance of Sr-doped materials. METHODS: We searched PubMed, EMBASE (via OVIDSP), and reference lists to identify relevant animal studies. The search, study selection, and data extraction were performed independently by two investigators. Meta-analyses and sub-group analyses were conducted using Revman version 5.4.1. The heterogeneity between studies were assessed by I2. Publication bias was investigated through a funnel plot. RESULTS: Thirty-five studies were finally enrolled, of which 16 articles that reported on new bone formation (NBF) were included in the meta-analysis, covering 31 comparisons and 445 defects. The overall effect for NBF was 2.25 (95% CI 1.61-2.90, p < 0.00001, I2 = 80%). Eight comparisons from 6 studies reported the outcomes of bone volume/tissue volume (BV/TV), with an overall effect of 1.42 (95% CI 0.65-2.18, p = 0.0003, I2 = 75%). Fourteen comparisons reported on the material remaining (RM), with the overall effect being -2.26 (95% CI - 4.02 to - 0.50, p = 0.0009, I2 = 86%). CONCLUSIONS: Our study revealed that Sr-doped calcium phosphate bone substitutes improved in vivo performance of bone repair. However, more studies are also recommended to further verify this conclusion.

Sinus Elevation Through Transcrestal Window Approach and Delayed Implant Placement in 1- to 2-mm Residual Alveolar Bone: A Case Report.

Sinus augmentation with a lateral window technique and delayed implant placement are the traditional treatment schedules when the residual alveolar bone height in atrophic posterior maxilla is less than 5 mm. This article presents a transcrestal window approach (TWA) to replace a missing first molar in an atrophic posterior maxillary ridge with 1 to 2 mm of residual bone height (RBH). Transcrestal sinus augmentation and delayed implant placement were performed. The antral pseudocyst that was located in the nasal wall of the maxillary sinus disappeared in the cone-beam computer tomography images taken after sinus elevation surgery. The 1-year follow-up visit showed that the implant was successful and the Periotest value was -4.8. This approach reduces discomfort to the patient. The TWA with an RBH of 1 to 2 mm is a minimally invasive method for maxillary sinus augmentation.

The effects of Er:YAG on the treatment of peri-implantitis: a meta-analysis of randomized controlled trials.

The clinical effectiveness of the erbium-doped yttrium-aluminum-garnet (Er:YAG) laser in patients with peri-implantitis remains unclear. The aim of this meta-analysis was to investigate the efficacy and safety of Er:YAG laser (ERL) compared to subgingival mechanical debridement (SMD) for the treatment of peri-implantitis. A systematic electronic literature search was conducted to identify randomized clinical trials (RCTs), followed by a manual search. Results were expressed as weighted mean differences (WMDs) with accompanying 95 % confidence intervals (CIs). The primary outcome measurements were changes in clinical attachment level (CAL) and probing depth (PD). Secondary outcome measurements included changes in gingival recession (GR). The meta-analysis was performed with fixed-effect or random-effect model according to the heterogeneity assessed by I (2) test. Visual asymmetry inspection of the funnel plot, Egger's regression test, and the trim-and-fill method were used to investigate publication bias. At 6 months, significant difference in PD reduction (p = 0.018) was observed for Er:YAG laser compared to SMD treatment, while no significant differences were detected in CAL gain and GR change; at 12 months, no significant difference was observed for any investigated outcome. The findings of this meta-analysis suggest that use of the Er:YAG laser as alternative to SMD could potentially provide short-time additional benefits, while there is no evidence of long-time superior effectiveness. As all included studies were not at low risk of bias, and only four studies were included in the meta-analysis, future long-term and well-designed RCTs reporting clinical and microbiological outcomes, considering the cost/effectiveness ratio, and having a high methodological quality are needed to clarify the effectiveness of Er:YAG laser.

A technique for immediate implant placement in mandibular multirooted teeth by the aid of a dynamic guidance system and preparing implant bed before tooth extraction.

Due to site-specific anatomical challenges, traditional immediate dental implant placement for mandibular multirooted molar sizes has many limitations. This technical report describes a modified approach for immediate dental implant placement in molar sites allowing for precise three-dimensional (3D) implant position and favourable clinical effect with the aid of a dynamic guidance system and flapless pre-extractive preparation of the implant bed.

Dual-guide template-guided socket-shield preparation and immediate implantation in maxillary anterior region implant surgery.

For immediate implants in the anterior region, the socket-shield technique has received much attention in recent years. However, this technique is technically sensitive and root preparation is difficult. It is also difficult to obtain the ideal three-dimensional position for implant placement in the anterior region. This paper reports a clinical case in which socket-shield preparation and implant cavity preparation were performed with the aid of a dual guide in implant surgery. The dual guide surgical preparation technique was used to reduce the difficulty of socket-shield preparation and to achieve restoration-orientated implant placement with satisfactory clinical results.

Cinnamaldehyde protects against ligature-induced periodontitis through the inhibition of microbial accumulation and inflammatory responses of host immune cells.

Cinnamaldehyde (CA), the main active ingredient in cinnamon, has been proved to be a potential candidate for controlling inflammation; however, there has been little evidence demonstrating its role in alleviating periodontitis. The aim of this study was to investigate the effect of orally administered CA on ligature-induced periodontitis in mice and the administration of CA on the Porphyromonas gingivalis (Pg) supernatant-induced inflammatory responses of murine macrophages and human periodontal ligament cells (HPDLCs). In vivo experiments showed that the oral administration of CA significantly inhibited bone resorption, the accumulation of anaerobic bacteria and host immuno-inflammatory responses in ligature-induced periodontitis in mice. In vitro, CA inhibited the expression of Pg supernatant-induced IL6, IL8, TNFA and IL1B and reactive oxygen species in RAW 264.7 and HPDLCs, involving the inactivation of the NFKB signaling pathway, which was activated by the Pg supernatant. Also, the expression of adherent and chemotactic-related cytokines was inhibited by CA, accompanied with a reduction in adherent HPDLCs. Moreover, CA ameliorated the cellular senescence of HPDLCs induced by H2O2, together with a decrease in senescence-associated-ß-galactosidase positive cells and decrease in the expression of P53, P21 and P16. Furthermore, CA promoted the osteogenic differentiation of HPDLCs with an increase in alkaline phosphatase expression and activity, formation of more mineralization nodules, and increased the expression of bone sialoprotein and osteopontin. Conclusions: Daily diet-added CA may be beneficial for oral health care, especially for the control of periodontic disease by suppressing the dysbiosis of biofilms and inhibiting the immunoinflammatory responses of migrated macrophages and local resident periodontal ligament cells to specific pathogen irritations.

Effectiveness of Platelet-Rich Fibrin as an Adjunctive Material to Bone Graft in Maxillary Sinus Augmentation: A Meta-Analysis of Randomized Controlled Trails.

PURPOSE: To date, it remains unknown whether the addition of platelet-rich fibrin (PRF) to bone grafts actually improves the effectiveness of maxillary sinus augmentation. This study aimed to perform a meta-analysis to evaluate the efficacy of PRF in sinus lift. MATERIALS AND METHODS: PubMed, Embase, and the Cochrane Library were searched. Randomized controlled studies were identified. The risk of bias was evaluated using the Cochrane Collaboration tool. RESULTS: Five RCTs were included in our meta-analysis. Clinical, radiographic, and histomorphometric outcomes were considered. No implant failure or graft failure was detected in all included studies within the follow-up period. The percentage of contact length between newly formed bone substitute and bone in the PRF group was lower but lacked statistical significance (3.90%, 95% CI, -2.91% to 10.71%). The percentages of new bone formation (-1.59%, 95% CI, -5.36% to 2.18%) and soft-tissue area (-3.73%, 95% CI, -10.11% to 2.66%) were higher in the PRF group but were not significantly different. The percentage of residual bone graft was not significant in either group (4.57%, 95% CI, 0% to 9.14%). CONCLUSIONS: Within the limitations of this review, it was concluded that there were no statistical differences in survival rate, new bone formation, contact between newly formed bone and bone substitute, percentage of residual bone graft (BSV/TV), and soft-tissue area between the non-PRF and PRF groups. Current evidence supporting the necessity of adding PRF to bone graft in sinus augmentation is limited.

Transalveolar sinus floor lift without bone grafting in atrophic maxilla: A meta-analysis.

We performed a meta-analysis aimed to assess the clinical results after transalveolar sinus floor lift without bone grafting in the atrophic maxilla. A systematic electronic literature search was conducted in PubMed, Embase and The Cochrane Library, followed by a manual search. Two reviewers independently extracted study data and conducted quality assessments. Ten non-controlled studies including 1484 implants and eight controlled studies (5 RCTs and 3 prospective studies) including 817 implants (451 implants in the non-graft group) were enrolled in this study. The survival rate of implants via the graft-free method was 98% (95%CI 96% to 100%). There was no significant difference in the survival rate between the non-graft group and the graft group (RR: 1.02; p = 0.18). No statistically significant difference in marginal bone loss was detected between the groups at 12 months (0.57, p = 0.07) or 36 months (0.05, p = 0.61). The endo-sinus bone gain in the non-graft group was significantly lower than in the graft group at 12 months (-1.10, p = 0.0001) and 36 months (-0.74, p = 0.02). Hence, the available evidence suggests that predictable results could be acquired through transalveolar sinus floor lift without bone grafting, while there may be a trend toward more endo-sinus bone gain with bone grafts.