RESUMEN
Critically-sized segmental bone defects represent significant challenges requiring grafts for reconstruction. 3D-printed synthetic bone grafts are viable alternatives to structural allografts if engineered to provide appropriate mechanical performance and osteoblast/osteoclast cell responses. Novel 3D-printable nanocomposites containing acrylated epoxidized soybean oil (AESO) or methacrylated AESO (mAESO), polyethylene glycol diacrylate, and nanohydroxyapatite (nHA) were produced using masked stereolithography. The effects of volume fraction of nHA and methacrylation of AESO on interactions of differentiated MC3T3-E1 osteoblast (dMC3T3-OB) and differentiated RAW264.7 osteoclast cells with 3D-printed nanocomposites were evaluated in vitro and compared with a control biomaterial, hydroxyapatite (HA). Higher nHA content and methacrylation significantly improved the mechanical properties. All nanocomposites supported dMC3T3-OB cells' adhesion and proliferation. Higher amounts of nHA enhanced cell adhesion and proliferation. mAESO in the nanocomposites resulted in greater adhesion, proliferation, and activity at day 7 compared with AESO nanocomposites. Excellent osteoclast-like cells survival, defined actin rings, and large multinucleated cells were only observed on the high nHA fraction (30%) mAESO nanocomposite and the HA control. Thus, mAESO-based nanocomposites containing higher amounts of nHA have better interactions with osteoblast-like and osteoclast-like cells, comparable with HA controls, making them a potential future alternative graft material for bone defect repair.
RESUMEN
Introduction: Periodontal disease and tongue coatings are among the major factors associated with oral malodor. The present study, comparatively evaluated the effects of the Er,Cr:YSGG laser and Halita mouthwash as adjunctive treatments to nonsurgical periodontal debridement on oral malodor reduction in chronic periodontitis patients. Methods: Sixty patients with stage II and III chronic periodontitis and bad breath. The patients were randomly divided into two groups (n=30). After conventional scaling and root planing, patients in group 1 underwent Er,Cr:YSGG laser (Waterlase; Biolase, San Clemente, CA, USA) irradiation of the internal surface of the pockets (1.5 W, 30 Hz, 20% A, 40% W) and the dorsum of the tongue (1 W, 30 Hz, 20% A, 40% W) immediately after SRP and on the third and seventh days. Group 2 patients were asked to use Halita mouthwash twice daily for one week. Baseline, 1 and 3-month post-treatment measurements of plaque index (PI), probing pocket depth (PPD), clinical attachment level (CAL), gingival index (GI), bleeding on probing (BOP) and organoleptic assessment of Halitosis severity were performed. Results: Significant improvement in all parameters was noted in both groups after 1 and 3 months, compared with baseline (P < 0.05). The two groups had significant reductions which occurred in PPD, CAL and BOP levels and the organoleptic score in 1 and 3 months after the intervention (P < 0.05). Conclusion: Er,Cr:YSGG laser irradiation and Halita mouthwash as adjuncts to non-surgical periodontal therapy are both effective in the treatment of oral malodor and improvement of periodontal parameters.
RESUMEN
Structural bone allografts are used to treat critically sized segmental bone defects (CSBDs) as such defects are too large to heal naturally. Development of biomaterials with competent mechanical properties that can also facilitate new bone formation is a major challenge for CSBD repair. 3D printed synthetic bone grafts are a possible alternative to structural allografts if engineered to provide appropriate structure with sufficient mechanical properties. In this work, we fabricated a set of novel nanocomposite biomaterials consisting of acrylated epoxidized soybean oil (AESO), polyethylene glycol diacrylate (PEGDA) and nanohydroxyapatite (nHA) by using masked stereolithography (mSLA)-based 3D printing. The nanocomposite inks possess suitable rheological properties and good printability to print complex, anatomically-precise, 'by design' grafts. The addition of nHA to the AESO/PEGDA resin improved the tensile strength and fracture toughness of the mSLA printed nanocomposites, presumably due to small-scale reinforcement. By adding 10 vol% nHA, tensile strength, modulus and fracture toughness (KIc) were increased to 30.8 ± 1.2 MPa (58% increase), 1984.4 ± 126.7 MPa (144% increase) and 0.6 ± 0.1 MPa·m1/2 (42% increase), respectively (relative to the pure resin). The nanocomposites did not demonstrate significant hydrolytic, enzymatic or oxidative degradation when incubated for 28 days, assuring chemical and mechanical stability at early stages of implantation. Apatite nucleated and covered the nanocomposite surfaces within 7 days of incubation in simulated body fluid. Good viability and proliferation of differentiated MC3T3-E1 osteoblasts were also observed on the nanocomposites. Taken all together, our nanocomposites demonstrate excellent bone-bioactivity and potential for bone defect repair.
