Journal of Functional Biomaterials最新文献

This study introduces innovative varnishes incorporating natural bioactive compounds to inhibit the formation of oral dual biofilms, a critical contributor to dental caries and other oral diseases. The purpose of this study was to evaluate the effectiveness of bioactive varnishes containing tt-farnesol, quercetin, and theobromine in inhibiting the formation of mixed Streptococcus mutans and Candida albicans biofilms. Mixed biofilms of Streptococcus mutans UA159 and Candida albicans SC5314 were grown in 96-well plates containing a specialized culture medium. Approximately 0.2 mL of experimental varnishes with A-1.5% or B-4.5% concentrations of tt-farnesol, quercetin, and theobromine were separately added to the wells using a disposable applicator, with a vehicle varnish (lacking bioactives) serving as the control. Biofilms were incubated at 37 °C with 5% CO₂ for 24 h. Microbial viability was determined in terms of colony-forming units per milliliter (CFU/mL), and biofilm morphology was evaluated qualitatively via scanning electron microscopy (SEM). Statistical analyses were performed using ANOVA/Tukey tests at a 5% significance level. Varnishes A and B achieved significant reductions in microbial populations within the biofilms (p < 0.05) compared to the vehicle control (C). SEM imaging revealed marked structural disruptions in the biofilms, validating the quantitative results. Higher bioactive concentrations demonstrated enhanced inhibitory effects. Bioactive varnishes enriched with theobromine, quercetin, and tt-farnesol represent a novel and effective strategy for inhibiting oral dual biofilm development, offering a promising advancement in preventive dentistry.

Resonance frequency analysis (RFA) has been used as a diagnostic method to measure implant stability at all stages of healing. In addition to evaluating the status of the peri-implant marginal bone, it can also indicate the most appropriate time to load the implant. This in vitro study aimed to evaluate the efficacy of RFA as a diagnostic method for the detection of peri-implant marginal bone loss (MBL). Forty bone-level Klockner Vega implants were placed in a polyurethane block with elastic properties similar to those of the maxillary bone. The insertion torque and primary implant stability at the time of placement were measured using an RFA device. A circumferential peri-implant defect was created by removing the cortical bone portion in each implant using a trephine. The stability values were measured again using RFA. The stability values measured using RFA were lower after the creation of the circumferential peri-implant defect, indicating a statistically significant decrease in implant stability. The results of the study tend to show a relationship between peri-implant marginal bone loss and modifications in implant stability measured by RFA.

Hydrogel network structures play a crucial role in determining mechanical properties and have broad applications in biomedical and industrial fields. Therefore, their rational design is essential. Herein, we developed a Schiff base-crosslinked hydrogel through the reaction of Tetra-armed polyethylene glycol with aldehyde end groups (Tetra-PEG-CHO) and bovine serum albumin (BSA) under alkaline conditions. In addition, the Tetra-PEG-BSA hydrogel showed a rapid gelation time of around 11 s, much faster than that of the GLU-BSA, HT-BSA, and GDL-BSA hydrogels. It had high optical transmittance (92.92% at 600 nm) and swelling ratios superior to the other gels in different solutions, maintaining structural integrity even in denaturing environments such as guanidine hydrochloride and SDS. Mechanical tests showed superior strain at break (84.12 ± 0.76%), rupture stress (28.64 ± 1.21 kPa), and energy dissipation ability (468.0 ± 34.9 kJ·m^-3), surpassing all control group hydrogels. MTT cytotoxicity assays indicated that cell viability remained >80% at lower concentrations, confirming excellent biocompatibility. These findings suggest that Tetra-PEG-BSA hydrogels may serve as effective materials for drug delivery, tissue engineering, and 3D printing.

Objectives: The objectives of this study were to investigate in vitro BPA release from two common fiberglass fixed lingual canine-to-canine retainers and to compare these amounts with those released from a conventional multistranded stainless-steel orthodontic retainer.

Methods: Fifty-four recently extracted teeth were divided into groups of six teeth each, formed in an arch shape. Three different retainer types were evaluated: Ribbond, EverStick Ortho and Wildcut wire. Three identical specimens were constructed for each retainer type. BPA release was determined with validated the liquid chromatography-tandem mass spectrometry method at 1 and 24 h, as well as at 7, 14 and 30 days. The method's limits of detection and quantification were 0.32 ng/mL and 0.96 ng/mL, respectively. A two-way mixed, repeated-measures analysis of variance with Greenhouse-Geisser correction was employed to verify the existence of any significant differences.

Results: Higher levels of BPA were released from the polyethylene fiber and glass fiber retainer in comparison with the conventional retainer in the present study. The differences between the systems over time were not statistically significant at the 95% confidence level.

Conclusions: In vitro BPA release during the first month did not differ between the examined retainer types. The highest BPA concentrations were observed at 1 month.

The aim of the present study was to test the sequential and simultaneous release of rhBMP2 and rhVEGF165 from poly-l-lysine-heparin (PLL-Hep) poly-electrolyte multilayer (PEM) coating on titanium surfaces for their ability to enhance peri-implant bone formation and CD31 expression around disc-shaped titanium implants (5 × 7 mm) in mini-pig mandibles. Bare titanium surfaces loaded with respective growth factor combinations served as controls. Ten different surface conditions were tested exhibiting early VEGF release, early BMP release, simultaneous VEGF and BMP release, and sole VEGF/BMP release, respectively. The implants were inserted press-fit into 5 mm trephine cavities at the lower border of the mandibles of mini-pigs and left to heal for 4 and 13 weeks. After 4 weeks, there was no significant difference in peri-implant bone formation, bone-implant contact nor CD31 expression between the different surface conditions. After 13 weeks, bone formation was significantly higher in the zone of 100 μm next to implant surfaces releasing either BMP alone or with an early release of BMP2. Expression of CD31 has significantly decreased from 4 to 13 weeks with significantly higher values in the group of implants with early release of BMP2. The results indicate that the range of released growth factors is limited to a distance of approximately 100 μm and that the sequence of early release of BMP2 followed by VEGF165 promotes peri-implant bone formation and peri-implant angiogenesis, which is in contrast to the current understanding of the temporal patterns of growth factor release for enhancement of bone formation.

Bacterial growth on implant surfaces poses a significant obstacle to the long-term success of dental and orthopedic implants. There is a need for implants that promote osseointegration while at the same time decreasing or preventing bacterial growth. In this study, the existing methods for the measurement of bacterial biofilms were adapted so that they were suitable for measuring the bacterial growth on implant surfaces. Two different strains of bacteria, Pseudomonas aeruginosa and Staphylococcus epidermidis, were used, and the in vitro effect of bacterial growth on titanium surfaces coated with an ultrathin (20-40 nm thick) layer of nanosized hydroxyapatite (nHA) was investigated. After 2 h of biofilm growth, there was a 33% reduction in both S. epidermidis and P. aeruginosa bacteria on nHA compared to Ti. For a more mature 24 h biofilm, there was a 46% reduction in S. epidermidis and a 43% reduction in P. aeruginosa on nHA compared to Ti. This shows that coating nHA onto implants could be of benefit in reducing implant-related infections.

The extraction of deeply impacted lower third molars is a common yet challenging surgical procedure associated with complications such as mandibular fractures, pain, and swelling. This study evaluated the effectiveness of customized 3D-printed titanium plates in reducing the risk of intraoperative iatrogenic mandibular fractures. This innovative approach aims to improve surgical outcomes, enhance patient safety, and boost confidence for both surgeons and patients. Eighteen patients with Pell and Gregory class II/IIIC impacted lower third molars underwent preoperative CBCT scans, which facilitated the design and fabrication of customized plates and drilling guides. The surgical procedure involved incision, flap elevation, precise plate placement, osteotomy, odontotomy, extraction, and the postoperative assessment of pain, swelling, trismus, and anxiety using validated scales and facial scanning. The results show that customized titanium plates successfully prevented mandibular fractures in all cases. Although initial postoperative discomfort, including swelling, trismus, and pain, was observed, significant improvements occurred within one week. This technique provided structural reinforcement during surgery and healing without adverse events or fractures. Customized 3D-printed titanium plates represent a safe and effective solution for minimizing mandibular fractures, offering promising improvements in surgical outcomes.

The aim of this study was to analyze the marginal bone loss and survival of implants in the augmented sinus area via the lateral window approach. The effect of sinus membrane perforation as well as splinting of the upper structure was analyzed. Two hundred and eighty-nine implants were placed in the sinus areas augmented with xenografts and collagen membranes in 101 patients. Clinical and radiographic data were obtained during recall visits. The Marginal Bone Loss (MBL) and Cumulative Survival Rate (CSR) were evaluated. The mean follow-up period was 12.4 years (range: 12 to 182 months). During the follow-up period, 19 implants were lost, yielding a 92.93% survival rate. No significant models for any of the covariates were found in terms of implant survival (p = 0.08). Similarly, no significant differences were observed between intact and perforated sinuses (p = 0.41) or between splinted or single standing implants (p = 0.11). The overall MBL reached 1.80 ± 0.56 mm at 15 years, and no significant differences were detected between any particular years (p = 0.12). Dental implant rehabilitation of the posterior maxilla via sinus augmentation using the lateral window technique is safe, effective and provides a high long-term implant survival with minimal prosthetic complications.

The nonunion and delayed union of bones are common challenges in orthopedic surgery, even when bone alignment is correct and sufficient mechanical stability is provided. To address this, artificial bone grafts are often applied to fracture gaps or defect sites to promote osteogenesis and enhance bone healing. In this study, we developed an alginate-based hydrogel incorporating gold nanoparticles (AuNPs) to enhance cell proliferation and facilitate bone healing through a photothermal effect induced by near-infrared (NIR) laser irradiation. The temperature was controlled by adjusting the AuNP content. The hydrogel's properties were characterized and cell viability was assessed. Our results indicate that while the incorporation of AuNPs slightly disrupted the hydrogel's cross-linking network at low concentrations, cell viability remained unaffected across both low and high AuNP contents. These findings suggest that this photothermal hydrogel holds great promise for orthopedic applications to improve bone healing.

Bone substitutes are commonly used in bone regeneration, and their functionalization with bioactive molecules can significantly enhance bone regeneration by directly influencing bone cells. This study aimed to evaluate the potential of raloxifene-functionalized Cerabone^® (CB) for promoting bone repair and to highlight the implications in bone regeneration. The effectiveness of Cerabone^® functionalized with raloxifene via sonication or gel delivery in promoting bone repair in rat calvaria defects was assessed. Ninety-six male rats with critical-sized calvarial defects were divided into six treatment groups (n = 16): COAG (spontaneous blood clot), CB (Cerabone^®), CBS (Cerabone^® sonicated alone), CBRS (Cerabone^® with raloxifene sonicated), CBG (Cerabone^® with gel vehicle), and CBRG (Cerabone^® with 20% raloxifene gel). After 14 and 28 days, samples were analyzed using microtomography, histomorphometry, immunohistochemistry, and fluorescence techniques. Quantitative data were statistically analyzed, comparing each group to the control CB group with significance set at p < 0.05. Micro-CT analysis demonstrated a significant increase in bone volume in the CBRS, CBRG, and CBS groups at 28 days compared to the CB group (p < 0.05). Specifically, the mean bone volume percentages for the CBRS, CBRG, CBS, and CB groups were 21.18%, 17.51%, 13.18%, and 7.8%, respectively. Histomorphometry showed increased new bone formation in the CBRS and CBRG groups at both 14 and 28 days. Fluorescence analysis revealed a significantly higher daily mineral apposition rate in the CBRS and CBRG groups at 28 days. These findings suggest that raloxifene-functionalized CB, delivered via sonication or gel, significantly enhances bone repair by improving bone volume and mineralization, highlighting its potential as an effective strategy for bone regeneration.