2018 Vol.26(11): 681–687    [Abstract] ( 144 )    [RICH HTML ] ( 28 )   [PDF 3326 KB ]( 152 )

The success of orthognathic surgery depends not only on surgical techniques but also on accurate and scientific surgical design and planning. The adoption of digital surgery has created a paradigm shift in surgical planning. However, compared with traditional methods, digital surgery-assisted planning of an orthognathic operation differs fundamentally from planning using traditional methods, including the elimination of plaster dental model surgery and of the increase in splint design accuracy. This article focuses on the application of digital virtual tools for pre-operative design of orthognathic surgery to provide a virtual surgical procedure reference for surgeons who need to incorporate digital surgery into orthognathic surgery.

2018 Vol.26(11): 688–698    [Abstract] ( 186 )    [RICH HTML ] ( 19 )   [PDF 1880 KB ]( 153 )

The traditional biological principle for developing bone biomaterials is to directly stimulate the osteogenic differentiation of osteoblastic lineage cells, the direct effector cells for osteogenesis. This strategy has been successful for the development of bone biomaterials. However, recent progress in bone biology has revealed the vital role of the local bone microenvironment, especially the immune environment, in controlling osteogenesis. Interdisciplinary osteoimmunology has found that the osteoimmune and skeletal systems are closely related, sharing numerous cytokines and regulators. In addition, immune cells play an important role in the physiological and pathological processes of the skeletal system, suggesting that neglecting the importance of the immune response is a major shortcoming of the traditional strategy. Based on this principle, we propose a novel “osteoimmunomodulation”-based strategy to meet the strict requirements of new-generation bone biomaterials: instead of directly regulating the osteogenic differentiation of osteoblastic lineage cells, we should focus more on manipulating the responses of immune cells and developing biomaterials to induce an immune environment that provides conditions that balance osteogenesis and osteoclastogenesis for optimal osseointegration. This article reviews the recent progress on osteoimmunology and immunomodulatory biomaterials for the generation of the “osteoimmunomodulation” concept. Additionally, the outcomes of “osteoimmunomodulation”-related studies have been summarized to guide the development of advanced “osteoimmune-smart” bone substitute materials.

2018 Vol.26(11): 699–705    [Abstract] ( 88 )    [RICH HTML ] ( 5 )   [PDF 3166 KB ]( 86 )

Objective To investigate the inductive effects of canine periodontal ligament stem cells (PDLSCs) cocultured with canine disparate differentiating-period iliac bone marrow stromal cells (I-BMSCs).Methods Purified PDLSCs were isolated by in vitro culture of cBMSCs and flow cytometry. Third-generation PDLSCs were obtained, and conditioned culture medium derived fromiliac bone marrow stromal cells (I-BMSCs-CM) was added as indicated for coculture of PDLSCs. As the control group, pure uninduced PDLSCs were routinely cultured in DMEM culture medium containing 15%FBS. The experimental groups included the I-BMSCs-CM, I-BMSCs-CM-10ds and I-BMSCs-CM-15ds groups. The I-BMSCs-CM group consisted of PDLSCs induced by I-BMSCs, the I-BMSCs-CM-10ds group consisted of PDLSCs induced by I-BMSCs after osteogenic induction for 10 days, and the I-BMSCs-CM-15ds group consisted of PDLSCs induced by I-BMSCs after osteogenic induction for 15 days. The cocultured PDLSCs were examined via the MTT assay. Total mRNA and protein were prepared at 3 and 7 days. The mRNA expression levels of runt-related transcription factor 2(Runx2), special AT-rich sequence binding protein 2(Satb2) and osteocalcin (OCN) were measured by qRT-PCR. The protein expression levels of Satb2, Runx2 and OCN were detected by Western blot.Results The PDLSCs showed a spindle-like morphology. While the BMSC-conditioned media increased PDLSCs proliferation, the media conditioned by BMSCs allowed to differentiate for 15 days (I-BMSCs-CM-15days) significantly enhanced PDLSCs proliferation (F=342.8, P=0.017). The expression levels of the analyzed genes were upregulated in the coculture groups, and the protein expression levels of Satb2, Runx2 and OCN were higher in the test groups than in the control group at 7 days. At the protein level, I-BMSCs-CM-15days upregulated the expression of Satb2 by 3.04-fold (FSatb2=24.48, P=0.014), Runx2 by 5.1-fold (FRunx2=12.25, P < 0.001), and OCN by 3.67-fold (FOCN=18.35, P=0.022).Conclusion The conditioned medium of I-BMSCs may enhance the proliferation of PDLSCs, and that of terminally differentiated bone cells probably triggered the osteogenesis of PDLSCs, suggesting important implications for periodontal engineering.

2018 Vol.26(11): 706–711    [Abstract] ( 123 )    [RICH HTML ] ( 4 )   [PDF 1431 KB ]( 77 )

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.

2018 Vol.26(11): 712–716    [Abstract] ( 104 )    [RICH HTML ] ( 8 )   [PDF 1494 KB ]( 84 )

Objective To investigate the short-term clinical effect of semiconductor laser exposure combined with total glucosides of paeony (TGP) capsules for the treatment of erosive oral lichen planus (OLP).Methods Sixty-four patients with erosive oral lichen planus were randomly divided into two groups: the experimental group and the control group. Patients in the control group were treated with TGP capsules, while patients in the experimental group were treated with TGP capsules and semiconductor laser irradiation. The clinical effects were evaluated 3 months after treatment. The data were analyzed using the SPSS 17.0 software package.Results Three months after treatment, the effective rate in the experimental group was 90.6%, which was significantly higher than that in the control group (59.4%, χ 2=5.62, P < 0.05). The physical condition and visual analogue scale (VAS) scores in the experimental group were 2.17 ± 1.49 and 1.25 ± 1.29, respectively. The physical condition and VAS scores in the control group were 3.55 ± 1.41 and 2.09 ± 1.24, respectively. The physical condition and VAS scores in both groups were significantly higher after treatment than before (P < 0.05). Three months after treatment, the physical condition score (t=3.805) and VAS score (t=2.655) in the experimental group were significant higher than those in the control group (P < 0.05). Conclusion Semiconductor laser irradiation combined with TGP capsules can improve the short-term clinical efficacy in the treatment of erosive OLP.

2018 Vol.26(11): 717–721    [Abstract] ( 179 )    [RICH HTML ] ( 15 )   [PDF 1025 KB ]( 96 )

Objective To analyze the morphology and incidence of middle mesial canal (MM) and isthmus in the mandibular first permanent molar by cone-beam computed tomography (CBCT).Methods Statistical analysis was performed on images from patients who underwent CBCT examination in the Department of Radiology at Stomatological Hospital, Southern Medical University. Samples exhibiting root canal treatment, root resorption and calcification were excluded. Data regarding sex, age, the presence or absence of isthmus and MM, and the number of roots and root canals were recorded.Results Of the 217 mandibular first molar samples, 8 (3.7%) had an MM, and 2 (0.9%) had an independent apical foramen. The overall incidence rate of isthmus was 57.1%; this rate was 50.7% in the cervical third of the root canal, 17.5% in the middle third, and 13.4% in the apical third. The incidence rate of isthmus was 61.8% on the left side, 52.3% on the right side, 58.7% in males, and 55.8% in females. No significant difference was found between the left and right sides or between females and males (P > 0.05). The incidence rate of isthmus in people under 60 was greater than 50% but was significantly lower in people older than 60.Conclusion Only a very small proportion of MMs have an independent apical foramen in the mandibular first molar. The incidence of isthmus in the mesial root of the mandibular first permanent molar is high, and isthmus usually occurs in the cervical third of the root canal. During root canal treatment or apical surgery, attention should be given to the physical and chemical preparation of the isthmus.

2018 Vol.26(11): 722–726    [Abstract] ( 432 )    [RICH HTML ] ( 18 )   [PDF 2386 KB ]( 110 )

Objective To compare the effect of the combined coronally advanced flap and connective tissue flap techniques with that of a guided tissue regeneration (GTR) technique on recovering the exposed root surface in a case of gingival retraction over the lower anterior teeth.Methods A case of gingival recession (Miller Ⅲ type) over teeth 33-43 accompanied by hypersensitivity of the right lower teeth was treated using different techniques bilaterally. Teeth 42-43 were treated by a combined coronally advanced flap and connective tissue flap technique, while teeth 33-41 were treated by a GTR technique of a coronally advanced flap combined with an absorbable collagen membrane.Results Teeth 42-43 exhibited ideal gingival recovering of the exposed root surface, with the disappearance of the hypersensitivity symptoms, during the follow-up visits at 3.5 months after surgery. However, the exposed root surface of teeth 33-41 exhibited no significant change in coverage at the same time points compared with the preoperative coverage. At 12 months after surgery, the recovered gingiva on the root surface of teeth 42-43 was stable.Conclusion The combined coronally advanced flap and connective tissue flap approach, which can achieve better coverage of the exposed root surface than the GTR technique, is a feasible and safe surgical method for treating cases with gingival recession. The GTR technique is not an effective method for treating cases with Miller Ⅲ type gingival recession over multiple teeth due to proximal attachment loss.

2018 Vol.26(11): 727–734    [Abstract] ( 161 )    [RICH HTML ] ( 11 )   [PDF 5895 KB ]( 91 )

Objective To investigate the reliability of using virtual articulator in the fabrication of zirconia crowns for tetracycline discolored teeth.Methods To treat the patient with serious tetracycline stained teeth, we use zirconia crowns to shield the stained abutment teeth. To retain the characteristics of patient′s original occlusal contacts, meanwhile, to establish a stable and evenly distributed occlusal contacts, we recorded the functional movements of the patient′s jaw before preparing the teeth and transferred this relations to a physical articulator. Afterwards, relationship of the upper and lower arches was scanned through a specified fixature. Then we can customized the fabrication of the occlusal contacts of the restorations conveniently and efficiently with virtual articulator in CAD/CAM system.Results When the final restorations were inserted , a charming smile was achieved on patient′s face with satisfactory esthetics. With the application of virtual articulator in designing process, we made evenly distributed and stable bilateral occlusal contacting spots, smooth protrusive and lateral guidance on the lingual aspects of the upper anteriors. One year follow-up, this patient was observed in good oral hygiene, and was satisfied with her esthetic and functional outcome. The soft tissue around the restorations was assessed to be healthy and no signs of inflammation.Conclusion Applying the virtual articulator kits in CAD/CAM system in designing and fabricating the function-driven restorations could be an efficient way to obtain an satisfactory long-term outcome.

2018 Vol.26(11): 734–737    [Abstract] ( 122 )    [RICH HTML ] ( 11 )   [PDF 705 KB ]( 102 )

The abuse of antibiotics has been increasing bacterial resistance, which means there is a need to develop methods for the efficient detection and effective treatment of multiresistant bacterial infections. As one of graphene-based materials, graphene quantum dots (GQDs) have distinct mechanical, electrical, and optical properties, including a small size, a large surface area-to-volume ratio, biocompatibility, antimicrobial activity and tunable photoluminescence. Therefore, GQDs are expected to be widely used as antimicrobial materials, drug delivery carriers and photosensitizers in antibacterial applications. In this review, we focus on their synthesis, characteristics and antimicrobial applications in oral medicine.

2018 Vol.26(11): 738–742    [Abstract] ( 125 )    [RICH HTML ] ( 8 )   [PDF 740 KB ]( 91 )

Electrospinning technology is currently the only technology capable of directly and continuously preparing polymer nanofibers. It can prepare a variety of nanofibers with different characteristics by using high voltage electrostatic field. These electrospun nanofibers have an inherently high porosity, high surface-to-volume ratio and good mechanical properties, allowing the engineering of scaffolds with a nanoscale topography and high porosity similar to that of the natural extracellular matrix (ECM) to facilitate cell attachment, migration, proliferation, differentiation and functional expression. Thus, electrospun nanofibers have been widely applied in tissue engineering for different purposes such as bone, cartilage, neural, vascular, and skin regeneration and are being developed for pulp regeneration. This review briefly describes the preparation process and biological characteristics of electrospun nanofibers; furthermore, the most recent and state-of-the-art work on electrospun nanofibrous scaffolds, primarily their composition and structure in pulp tissue engineering, is introduced.

2018 Vol.26(11): 743–748    [Abstract] ( 238 )    [RICH HTML ] ( 48 )   [PDF 760 KB ]( 222 )

The Invisalign system has been used in the clinic for nearly two decades and its invisible, comfortable and beautiful features are increasingly favored by doctors and patients. In recent years, Invisalign technology is constantly innovating from mild crowding (G1), relatively complicated tooth movement (G2), anterior tooth torque control (G3), anterior open bite (G4), deep overbite (G5), first four premolar extraction (G6), and posterior open bite (G7) to the correction of skeletal class Ⅱmalocclusion in adolescents. Its indications has covered almost all areas of traditional fixed orthodontics. However, as this technology is in the developmental stage, there is a discontinuity between the computer-designed positioning and the clinical results. Although Invisalign has manifested excellent performance in correcting tooth intrusion, tipping movement and distal movement, its ability to correct tooth rotation and extrusion still needs improvement. This paper reviews the characteristics of Invisalign G1-G7 and Invisalign MA and the efficacy of these systems in correcting different types of tooth movement.