Age-dependent effects of transverse maxillary deficiency treated by microimplant-assisted rapid palatal expansion: A prospective cone-beam computed tomography study.

INTRODUCTION: This study investigated the results of maxillary discrepancy treated by microimplant-assisted rapid palatal expansion (MARPE) at different ages. METHODS: Sixty patients (aged 11.0-34.1 years; 23 male and 37 female) were treated by MARPE. Cone-beam computed tomography scans and dental casts were taken before and after expansion. The data were compared among 4 age groups: early adolescents (aged 11-14 years), late adolescents (aged 15-19 years), young adults (aged 20-24 years), and old adults (aged 25-34.1 years). RESULTS: The success rates of midpalatal suture separation were 100%, 100%, 88.2%, and 85.7% for early adolescents, late adolescents, young adults, and old adults, respectively. Palatal sutures at the level of the first molar were expanded by 4.02 mm, 3.48 mm, 2.63 mm, and 2.10 mm, corresponding to 66.7%, 58.1%, 42.0%, and 37.9% of the total dental expansion. Significant differences were found in the amounts of palatal suture expansion and the ratio of skeletal dental expansion between patients aged <20 years and patients aged ≥20 years (P <0.05). Skeletal expansion constituted 69.4%, 51.3%, 39.0%, and 29.8% of the total screw expansion. Except for the comparison between young adults and old adults, there were significant differences between groups for the ratio of skeletal screw expansion (P <0.05). CONCLUSIONS: The midpalatal suture can be expanded by MARPE more easily in patients <20 years of age than in patients ≥20 years of age. The ratio of skeletal screw expansion decreases as age increases.

Oral polysaccharide-coated liposome-modified double-layered nanoparticles containing anthocyanins: preparation, characterization, biocompatibility and evaluation of lipid-lowering activity in vitro.

Anthocyanins (ACNs) systems encapsulated in nanomaterials have received widespread attention and rapid development due to its good delivery potential. Here, the favorable benefits of four natural polysaccharide food additives coated ACNs-liposome nanoparticles (ACNs-Lipo NPs) on the stability and possible lipid-lowering effects of ACNs are discussed in this work. The polysaccharides were coupled to the ACNs-Lipo NPs and self-assembled to create ACNs-Lipo@polysaccharide NPs. The impact of various polysaccharides on the physical, chemical, and stability characteristics of NPs was examined. We found that the NPs prepared with gum arabic (GA) had the best stability. FT-IR and XRD analysis revealed electrostatic adsorption and hydrogen binding forces between the components, as well as an amorphous structure. A series of tests in vitro confirmed the excellent stability, bioavailability, antioxidant activity, and biocompatibility of NPs. Finally, cellular antioxidant activity (CAA) and oleic acid (OA)-induced lipid deposition cell models revealed that ACNs-Lipo@GA might be more readily absorbed by cells, resulting in improved antioxidant activity and lipid-lowering impact, with possible targeted delivery qualities and lipid-lowering effect.

The experimental research on two-generation BLB dental implants - part I: surface modification and osseointegration.

OBJECTIVE: The study was designed to evaluate the comparative effect of osseointegration induced by the dental implants of Beijing Leiden Biomaterial (BLB) and BLBIII. MATERIALS AND METHODS: The surface properties ofBLBI and BLBIII were studied through thermal field-scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDS) and optical profilometer. A total of 36 BLBI and BLBIII implants, with each of the two groups possessing 18, were randomly implanted into the extraction fossa of the mandibular premolar areas of six Beagles. The animals were then executed 2, 4 and 8 weeks after the surgery, which was followed by macroscopic examination and histomorphometric analysis. RESULTS: Typical cloud-form microstructure was found on the surface of BLBI implant, which was distributed widely yet in an irregular way. The surface of BLBIII implant was mainly featured by a highly porous layer. The EDS spectra of BLBI indicated the peaks of calcium (Ca) and phosphorous (P) compatible with apatite phase, while the peaks of Ca, P, oxygen and titanium were incorporated in the BLBIII group. The ratio of Ca and K showed no significant differences in the surface chemical composition of BLBI and BLBIII. Surface microtopographic analysis showed a statistical difference (P<0.01) in the roughness between BLBI (R(a)) and BLBIII. In the healing period, a larger amount of osteoid and bone tissues were observed in the areas surrounding the BLBIII group than those of the BLBII group. After 2 and 4 weeks of the surgery, the bone-implant contact (BIC) of BLBIII group presented higher value of statistical significance (P<0.05) than that of BLBI. However, after the 8-week healing period, the BIC difference between the two groups proved to be of no statistical significance (P>0.05). CONCLUSION: Micro-arc oxidation (MAO) and electrophoresis deposition (EPD) are able to produce a highly porous layer on the surface of BLBIII, which is characterized by a relatively stable Ca/P ratio similar to that of the hydroxyapatite layer. Therefore, superior and early osseointegration potential was demonstrated in the threaded implants treated by MAO coupling with EPD, rather than the merely cylindrical-shaped ones with plasma-sprayed HA coating layer.

Simvastatin intervention mitigates hypercholesterolemia-induced alveolar bone resorption in rats.

Simvastatin promotes bone formation and increases bone mineral density in patients with hyperlipidemia and ameliorates hypercholesterolemia-induced microstructure changes in the jaw bone of animals. However, whether and how treatment with simvastatin can modulate the hypercholesterolemia-induced alveolar bone resorption is unclear. The present study aimed to examine the therapeutic efficacy and potential mechanisms of simvastatin application in hypercholesterolemia-induced alveolar bone resorption. The association between hyperlipidemia and alveolar bone resorption in 100 patients with periodontitis was examined. Additionally, male Sprague-Dawley rats were fed a standard rodent chow (NC) for 32 weeks or a high cholesterol diet (HCD) for 24 weeks. The HCD-fed rats were randomized, continually fed with HCD and treated with vehicle saline (HC) or simvastatin by gavage (5 mg/kg; SIM, n=10/group) for 8 weeks. The morphological changes to alveolar bone resorption in rats were analyzed by linear measurements. The relative levels of osteoprotegerin (OPG), receptor activator of nuclear factor-κB ligand RANKL, nuclear factor-κB (NF-κB), microtubule-associated protein 1 light chain 3 (LC3) and p62 in the alveolar bone tissues were determined by reverse transcription-quantitative PCR and/or immunohistochemistry. Sulcus bleeding index (SBI), clinical attachment loss (CAL), probing depth (PD) and the distance of cemantoenamel junction-alveolar bone crest (CEJ-ABC) in patients with hyperlipidemia were significantly greater than that in the controls (P<0.001). The levels of hyperlipidemia were positively correlated with the values of SBI, CAL, PD and CEJ-ABC in this population. Compared with the NC rats, higher levels of alveolar bone resorption, NF-κB expression, higher ratios of RANKL/OPG mRNA transcripts and LC3 to p62 expression were detected in the alveolar bone tissues of HC group. Simvastatin intervention significantly mitigated hypercholesterolemia-induced alveolar bone loss and RANKL mRNA transcription, but increased the ratios of LC3/p62 protein expression in the alveolar bone tissues of rats. Hyperlipidemia is associated with alveolar bone resorption and simvastatin treatment alleviated the hypercholesterolemia-related alveolar bone loss by down-regulating the NF-κB expression.

Comparison of skeletal maxillary transverse deficiency treated by microimplant-assisted rapid palatal expansion and tooth-borne expansion during the post-pubertal growth spurt stage.

OBJECTIVE: To investigate the efficacy of microimplant-assisted rapid palatal expansion (MARPE) to treat skeletal maxillary discrepancies during the post-pubertal growth spurt stage. MATERIALS AND METHODS: Sixty patients with skeletal maxillary transverse deficiency during the post-pubertal growth spurt stage were randomly divided into MARPE and Hyrax groups. Thirty patients (mean age: 15.1 ± 1.6 years) were treated using the four-point MARPE appliance; 30 patients (mean age, 14.8 ± 1.5 years) were treated using the Hyrax expander. Cone beam computed tomography scans and dental casts were obtained before and after expansion. The data were analyzed using paired t-tests and independent t-tests. RESULTS: The success rates of midpalatal suture separation were 100% and 86.7% for MARPE and Hyrax groups, respectively. Palatal expansion and skeletal to dental ratio at the first molar level were greater in the MARPE group (3.82 mm and 61.4%, respectively) than in the Hyrax group (2.20 mm and 32.3%, respectively) (P < .01). Reductions in buccal alveolar bone height and buccal tipping of the first molars were less in the MARPE group than in the Hyrax group (P < .01). CONCLUSIONS: MARPE enabled more predictable and greater skeletal expansion, as well as less buccal tipping and alveolar height loss on anchorage teeth. Thus, MARPE is a better alternative for patients with skeletal maxillary deficiency during the post-pubertal growth spurt stage.

kgp, rgpA, and rgpB DNA vaccines induce antibody responses in experimental peri-implantitis.

BACKGROUND: Peri-implantitis is the key factor for implant failure. This study aims to evaluate kgp, rgpA, and rgpB DNA vaccines to induce an immune response and prevent peri-implantitis. METHODS: The kgp, rgpA, and rgpB genes were amplified by polymerase chain reaction (PCR) from Porphyromonas gingivalis (Pg) ATCC 33277 and cloned into the pVAX1 vector. Titanium implants were placed into the mandibular bone of dogs. Three months later, the animals were divided into four groups, immunized with pVAX1-kgp, pVAX1-rgpA, pVAX1-rgpB, or pVAX1. Cotton ligatures infiltrated with Pg were tied around the neck of the implants. Immunoglobulin (Ig)G and IgA antibodies were detected by enzyme-linked immunosorbent assay before and after immunization. RESULTS: The kgp, rgpA, and rgpB genes were successfully cloned into the pVAX1 plasmid. Animals immunized with pVAX1-kgp and pVAX1-rgpA showed higher titers of IgG and IgA antibodies compared to those before immunization (P <0.05) and compared to those that were immunized with pVAX1 and pVAX1-rgpB, whereas there were no significant differences in the animals treated with pVAX1 and pVAX1-rgpB. Furthermore, among these, the kgp DNA vaccine was more effective. The bone losses of the groups with pVAX1-kgp and pVAX1-rgpA were significantly attenuated. CONCLUSION: pVAX1-kgp and pVAX1-rgpA DNA vaccines enhanced immunity responses and significantly retarded bone loss in experimental peri-implantitis animal models, whereas pVAX1-rgpB was ineffective.

rgpA DNA vaccine induces antibody response and prevents alveolar bone loss in experimental peri-implantitis.

BACKGROUND: Peri-implantitis is one of many reasons for dental implant failure. This study is designed to prevent experimental peri-implantitis by arginine-specific gingipain A (rgpA) DNA vaccine. METHODS: The bilateral mandibular second and third premolars from 15 male beagle dogs were extracted, and 60 implants were immediately implanted. Three months after implantation, the animals were randomly divided into groups A, B, and C and immunized with plasmid vector-rgpA, heat-killed Porphyromonas gingivalis, and plasmid vector, respectively. Cotton ligatures infiltrated with P. gingivalis were placed in the submarginal position around the neck of the implants to induce peri-implantitis. Clinical measurements, including probing depth (PD) and bleeding on probing, were recorded every 2 weeks postoperatively, and P. gingivalis-specific immunoglobulin G (IgG) in serum and secretory IgA (sIgA) in saliva were quantitatively analyzed by enzyme-linked immunosorbent assay at the same time. Animals were sacrificed after 6 weeks, 50-µm undecalcified histologic sections were prepared using methylene blue dye, and bone loss around implants was measured. RESULTS: Higher levels of IgG in serum and sIgA in saliva could be measured in groups A and B but not in group C after immunization. There were statistical differences (P <0.05) between, before, and after immunization, but no difference was found between groups A and B (P >0.05). Both peri-implant PD and bone loss in group A were significantly less than in groups B and C. CONCLUSIONS: IgG and sIgA could be generated by immunization with rgpA DNA vaccine, which could significantly slow down bone loss in the experimental peri-implantitis canine model.