Long-Term Follow-Up of a Novel Surgical Option Combining Fibula Free Flap and 3D-Bioprinted, Patient-Specific Polycaprolactone (PCL) Implant for Mandible Reconstruction.

As the fibula free flap became the gold standard in mandibular reconstruction that required both hard tissue and soft tissue, various methods have been sought to solve the height discrepancy between the mandible and fibula. The purpose of this paper was to propose a surgical option that combined the microvascular fibula free flap with a 3D-bioprinted, patient-specific polycaprolactone (PCL) implant as a safe and simple novel method that achieved the best functional and aesthetic results in mandibular reconstruction surgery for young patients with malignant tumors. The patient's reconstructed mandible maintained volume symmetry without any deformation or complications for over 6 years. Computer-aided design/computer-aided manufacturing (CAD/CAM) and 3D printing technology enabled accurate and safe surgical results.

A case series of profilometric changes in two implant placement protocols at periodontally compromised non-molar sites.

Information regarding profilometric changes at a soft tissue level following implant placement with different protocols is insufficient. Therefore, this study aimed to comparatively investigate the profilometric tissue changes with respect to late implant placement following alveolar ridge preservation (LP/ARP) and early implantation (EP) in periodontally compromised non-molar extraction sites. Sixteen patients were randomly assigned to the following groups: implant placement 4 months post-ARP (group LP/ARP) and tooth extraction and implant placement 4-8 weeks post-extraction (group EP). Dental impressions were obtained immediately after final prosthesis insertion and at 3, 6, and 12 months. At the time of implant placement, bone augmentation was performed in the majority of the patients. Profilometric changes of the tissue contour were minimal between the final prosthesis insertion and 12 months in the mid-facial area (0.04-0.35 mm in group LP/ARP, 0.04-0.19 mm in group EP). The overall tissue volume increased in both groups (1.70 mm3 in group LP/ARP, 0.96 mm3 in group EP). In conclusion, LP/ARP and EP led to similar stability of the peri-implant tissue contour between the final prosthesis insertion and at 12 months. Moreover, the change of peri-implant tissue on the soft tissue level was minimal in both modalities.

Setting the sagittal condylar inclination on a virtual articulator by using a facial and intraoral scan of the protrusive interocclusal position: A dental technique.

Setting the condylar inclination of a dental articulator enables the delivery of prostheses without occlusal interferences. This technique article describes obtaining the sagittal condylar inclination (SCI) by using a facial and an intraoral scan of the protrusive interocclusal position. The SCI can be used on a virtual articulator in dental computer-aided design (CAD) software programs, which can facilitate the fabrication of functional prostheses without occlusal interferences.

Setting the Sagittal Condylar Inclination on a Virtual Articulator Using Intraoral Scan of Protrusive Interocclusal Position and Cone Beam Computed Tomography.

The articulator is a prerequisite device for the analysis of occlusion and prosthodontic treatment, and it is required to simulate patient jaw movements. This article describes the technique to obtain sagittal condylar inclination (SCI) using cone beam computed tomography (CBCT) data and intraoral scan of the protrusive interocclusal position. The SCI can be used on a virtual articulator in a computer-aided design software, and it can assist in the fabrication of prosthesis which is harmonious with the mandibular movement of individual patient.

Oral Soft Tissue Regeneration Using Nano Controlled System Inducing Sequential Release of Trichloroacetic Acid and Epidermal Growth Factor.

BACKGROUND: The effect of nano controlled sequential release of trichloroacetic acid (TCA) and epidermal growth factor (EGF) on the oral soft tissue regeneration was determined. METHODS: Hydrophobically modified glycol chitosan (HGC) nano controlled system was developed for the sequential release of TCA and EGF, and the release pattern was identified. The HGC-based nano controlled release system was injected into the critical-sized defects created in beagles' palatal soft tissues. The palatal impression and its scanned body was obtained on various time points post-injection, and the volumetric amount of soft tissue regeneration was compared among the three groups: CON (natural regeneration control group), EXP1 (TCA-loaded nano controlled release system group), EXP2 (TCA and EGF individually loaded nano controlled release system). DNA microarray analysis was performed and various soft tissue regeneration parameters in histopathological specimens were measured. RESULTS: TCA release was highest at Day 1 whereas EGF release was highest at Day 2 and remained high until Day 3. In the volumetric measurements of impression body scans, no significant difference in soft tissue regeneration between the three groups was shown in two-way ANOVA. However, in the one-way ANOVA at Day 14, EXP2 showed a significant increase in soft tissue regeneration compared to CON. High correlation was determined between the histopathological results of each group. DNA microarray showed up-regulation of various genes and related cell signaling pathways in EXP2 compared to CON. CONCLUSION: HGC-based nano controlled release system for sequential release of TCA and EGF can promote regeneration of oral soft tissue defects.

A technique for transferring the contours of a functional impression to the polished surfaces of digitally fabricated removable complete dentures.

For the retention and stability of removable complete dentures, the denture base should be fabricated with appropriate borders and polished surfaces. A technique for transferring the contour of a functional impression for digitally fabricated removable complete dentures is described.

Combining Conventional Impressions and Intraoral Scans: A Technique for the Treatment of Complete Denture Patients with Flabby Tissue.

The conventional method for impressions of flabby tissue uses modified trays and highly flowable materials, but mucostatic impressions are difficult to achieve due to the viscous and the elastic natures of impression materials. In this report, a technique is presented in which conventional impression and intraoral scanning for a fully edentulous patient with flabby tissue are combined. The definitive impression was obtained by applying appropriate pressure to each tissue area, and the denture can be maintained passively and stable at rest and during function.

Comparing accuracy of denture bases fabricated by injection molding, CAD/CAM milling, and rapid prototyping method.

PURPOSE: The accuracy of denture bases was compared among injection molding, milling, and rapid prototyping (RP) fabricating method. MATERIALS AND METHODS: The maxillary edentulous master cast was fabricated and round shaped four notches were formed. The cast was duplicated to ten casts and scanned. In the injection molding method, designed denture bases were milled from a wax block and fabricated using SR Ivocap injection system. Denture bases were milled from a pre-polymerized block in the milling method. In the RP method, denture bases were printed and post-cured. The intaglio surface of the base was scanned and surface matching software was used to measure inaccuracy. Measurements were performed between four notches and two points in the mid-palatal suture to evaluate inaccuracy. The palatine rugae resolution was evaluated. One-way analysis of variance was used for statistical analysis at α=.05. RESULTS: No statistically significant differences in distances among four notches (P>.05). The accuracy of the injection molding method was lower than those of the other methods in two points of the mid-palatal suture significantly (P<.05). The degree of palatine rugae resolution was significantly higher in the injection molding method than that in other methods (P<.05). CONCLUSION: The overall accuracy of the denture base is higher in milling and RP method than the injection molding method. The degree of fine reproducibility is higher in the injection molding method than the milling or RP method.

Precise Reproduction of Soft Tissue Structure around the Pontic Area Using Computer-Aided Design and Manufacturing.

Reproducing soft tissue contours around a pontic area is important for the fabrication of an esthetic prosthesis, especially in the anterior area. A gingival model that precisely replicates the soft tissue structure around the pontic area can be easily obtained by taking a pick-up impression of an interim fixed dental prosthesis. After a working cast is fabricated using the customary technique, the pick-up model is superimposed onto the working model for the pontic area using computer-aided design and manufacturing (CAD/CAM). A definitive restoration using this technique would be well adapted to the pontic base, which is formed by the interim prosthesis.

Effects of moderate intensity static magnetic fields on osteoclastic differentiation in mouse bone marrow cells.

Although we recently demonstrated that static magnetic fields (SMFs) of 3, 15, and 50 mT stimulate osteoblastic differentiation, the effects of SMFs on osteoclastogenesis are still poorly understood. This study focused on the suppressive effects of SMFs on receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclastogenesis and bone resorption. Direct SMFs inhibit RANKL-induced multinucleated osteoclast formation, tartrate-resistant acid phosphatase activity, and bone resorption in mouse bone marrow-derived macrophage cells. The conditioned medium from osteoblasts treated with SMFs also resulted in the inhibition of osteoclast differentiation as well as resorption. The RANKL-induced expression of osteoclast-specific transcription factors, such as c-Fos and NFATc1, was remarkably downregulated by SMF at 15 mT. In addition, SMF inhibited RANKL-activated Akt, glycogen synthase kinase 3ß (GSK3ß), extracellular signal-regulated kinase, c-jun N-terminal protein kinase, mitogen-activated protein kinase (MAPK), and nuclear factor-κB (NF-κB) formation. These findings indicate that SMF-mediated attenuation of RANKL-induced Akt, GSK3ß, MAPK, and NF-κB pathways could contribute to the direct and indirect inhibition of osteoclast formation and bone resorption. Therefore, SMFs could be developed as a therapeutic agent against periprosthetic or peri-implant osteolysis. Additionally, these could be used against osteolytic diseases such as osteoporosis and rheumatoid arthritis. Bioelectromagnetics. 39:394-404, 2018. © 2018 Wiley Periodicals, Inc.

A 10-Year Cone Beam Computerized Tomography Observation of the Buccal Bony Wall of an Immediately Placed Implant at the Anterior Maxilla: A Case Report.

Since the introduction of immediate implant placements, the buccal bony wall has been a major consideration for success due to its correlation with soft tissue contour and color. This report presents the stability of the buccal wall thickness of an immediately placed implant at the anterior maxilla over 10 years. Although the width of the buccal wall decreased at the 2-year post-op follow-up, it remained stable afterward according to cone beam computerized tomography (CBCT) scans. Hence, this report suggests that ensuring adequate bony wall thickness with bone augmentation and fixture position may promise the longevity of the buccal bony wall and surrounding soft tissue in an immediate implant placement.

Stress analysis of mandibular implant overdenture with locator and bar/clip attachment: Comparative study with differences in the denture base length.

PURPOSE: The design of the attachment must provide an optimum stress distribution around the implant. In this study, for implant overdentures with a bar/clip attachment or a locator attachment, the stress transmitted to the implant in accordance with the change in the denture base length and the vertical pressure was measured and analyzed. MATERIALS AND METHODS: Test model was created with epoxy resin. The strain gauges made a tight contact with implant surfaces. A universal testing machine was used to exert a vertical pressure on the mandibular implant overdenture and the strain rate of the implants was measured. RESULTS: Means and standard deviations of the maximum micro-deformation rates were determined. 1) Locator attachment: The implants on the working side generally showed higher strain than those on the non-working side. Tensile force was observed on the mesial surface of the implant on the working side, and the compressive force was applied to the buccal surface and on the surfaces of the implant on the non-working side. 2) Bar/clip attachment: The implants on the both non-working and working sides showed high strain; all surfaces except the mesial surface of the implant on the non-working side showed a compressive force. CONCLUSION: To minimize the strain on implants in mandibular implant overdentures, the attachment of the implant should be carefully selected and the denture base should be extended as much as possible.

A Method for Minimizing Rotational Errors of Implant Prostheses.

PURPOSE: Rotational errors of implants can occur during two stages: when connecting impression copings with implants, and when connecting impression copings with analogs. The aim of this study was to determine ways to minimize these rotational errors. MATERIALS AND METHODS: Three types of implants were prepared: a tissue-level implant with an internal octagon 8-degree Morse taper connection, a bone-level implant with an internal hex 11-degree Morse taper connection, and a bone-level implant with an external hex connection. Each complex (n = 10 per group) was composed of an implant, an impression coping, and an analog. Implants were embedded in resin blocks and connected with corresponding impression copings. Analogs that reproduced the position of the implants were created by means of a custom-made transfer jig, and rotational errors were measured between implants and analogs. Impression copings and analogs were connected by means of four methods: The impression coping was connected to the implant in a clockwise (CW) or a counterclockwise (CCW) direction before tightening, and the analogs were then connected with impression copings and tightened using a hemostat (Hs) or by hand (Hd). RESULTS: The CW-Hs and CCW-Hd groups exhibited low rotational error (mean ± standard deviation 0.11 ± 0.21 and 0.19 ± 0.34 degrees, respectively), whereas the CW-Hd and CCW-Hs groups exhibited high rotational error (-1.80 ± 0.67 and 2.07 ± 0.75, respectively) in different directions. A strong association was observed between the tightening method and rotational error, and a weak association was observed between the connection type and rotational error. CONCLUSION: The CW-Hs method was found to be the most suitable for minimizing rotational error between implants and analogs.

A simplified method for evaluating the 3-dimensional cement space of dental prostheses by using a digital scanner.

Evaluating the cement space of various dental prostheses is important because it is related to the stability and retention of the prosthesis. However, a method for evaluating an overall cement space is complex. The purpose of this technique was to simplify the evaluation of prosthesis cement space by using a digital scanner. The form and thickness of the cement space could be simply recognized in any section the clinician or dental researcher wishes. Moreover, the cement space of several dental prostheses for the same abutment could also be precisely evaluated by superimposition. The method can be applied to various prosthodontic treatments.

Dual Effect of Curcumin/BMP-2 Loaded in HA/PLL Hydrogels on Osteogenesis In Vitro and In Vivo.

In the present study, we evaluated the potential of poly-l-lysine/hyaluronic acid (HA/PLL) hydrogels containing curcumin (CUR) and bone morphogenetic protein-2 (BMP-2) as bone tissue regeneration scaffolds. Hydrogels HP-1˜2 were formed by amide bonds via the condensation reactions between 0.02 µmol HA and 0.06­0.12 µmol poly-l-lysine · hydrobromide (PLL · HBr). Physical, chemical, and thermal analyses revealed that the amount of PLL · HBr significantly influenced hydrogel properties. Based on an In Vitro MG-63 cell proliferation test, HP-1˜2 were cytocompatible, and all hydrogels containing different amounts of CUR and BMP-2, except for HA0.02/PLL0.06/CUR20/BMP-2100 (HPCB-4), resulted in cell proliferation above 80%. An In Vitro release test showed that CUR and BMP-2 were consistently released from HA0.02/PLL0.06/CUR15 (HPC), HA0.02/PLL0.06/BMP-2100 (HPB), HA0.02/PLL0.06/CUR15/BMP-210 , 50 , or 100 (HPCB-1˜3), and HA0.02/PLL0.06/CUR10 or 20/BMP-2100 (HPCB-4˜5) for 7 and 28 days, respectively. In Vitro ALP activity and calcium deposition and In Vivo micro-computed tomography (micro-CT) tests demonstrated the potential application of HPCB-3 as bone tissue regeneration scaffolds, suggesting that bone tissue regeneration can be optimized by controlling the amounts of CUR and BMP-2.

Supramolecular Hydrogels Based on MPEG-Grafted Hyaluronic Acid and α-CD Containing HP-ß-CD/Simvastatin Enhance Osteogenesis In Vivo.

Simvastatin (SIM) accelerates new bone formation both in vitro and In Vivo by enhancing the expression of recombinant human bone morphogenetic protein-2 (rhBMP-2). In this study, we evaluated the effect of water-solubility of SIM on new bone formation by preparing two types of supramolecular hydrogels: pseudopolyrotaxanes (PPRXs) based on metoxy polyethyleneglycol-grafted hyaluronic acid (MPEG-g-HA) and α-cyclodextrin (α-CD) containing water-soluble hydroxypropyl ß-cyclodextrin/simvastatin inclusion complex (HP-ß-CD-ic-SIM; MPEG-g-HA/α-CD/HP-ß-CD-ic-SIM) or only SIM (MPEG-g-HA/α-CD/SIM). As compared to MPEG-g- HA/α-CD/SIM, SIM was more rapidly released from MPEG-g-HA/α-CD/HP-ß-CD-ic-SIM in a sustained manner owing to increased water-solubility. New bone actively formed at the calvarial defect site in a rabbit model 4 weeks after implantation, as examined by micro computed tomography (micro CT), hematoxylin and eosin (H&E) staining, and Goldner's trichrome staining. The results showed that the water-solubility of SIM plays a significant role in enhancing new bone formation in vivo.

Fabrication of a CAD/CAM monolithic zirconia crown to fit an existing partial removable dental prosthesis.

Fabricating a surveyed prosthesis beneath an existing partial removable dental prosthesis (PRDP) is a challenging and time-consuming procedure. The computer-aided design/computer-assisted manufacturing (CAD/CAM) technology was applied to fabricate a retrofitted, surveyed zirconia prosthesis to an existing PRDP. CAD/CAM technology enabled precise and easy replication of the contour of the planned surveyed crown on the existing abutment tooth. This technology ensured excellent adaptation and fit of newly fabricated crown to the existing PRDP with minimal adjustments. In this case report, a seventy-year-old male patient presented with fractured existing surveyed crown. Because the existing PRDP was serviceable, new crown was fabricated to the existing PRDP.

Comparative Analysis of Screw Loosening With Prefabricated Abutments and Customized CAD/CAM Abutments.

PURPOSE: The aim of this study was to determine the stability of computer-aided design and manufacturing (CAD/CAM) and prefabricated abutment by measuring removal torque before and after cyclic loading. MATERIALS AND METHODS: Three types of fixture and 2 types of abutments were used. Removable torque was measured after cyclic loading for 5000 cycles between 25 and 250 N for each group. The same procedure was performed twice. RESULTS: First, removal torque values (Newton centimeter) were measured for stock versus custom abutments as follows: group 1: 27.17 versus 26.67, group 2: 26.27 versus 26.33, and group 3: 37.33 versus 36.67. Second removal torque values (Newton centimeter) were also measured: group 1: 23 versus 23.5, group 2: 22.5 versus 22.33, and group 3: 32.67 versus 32.5. There was no significant difference between the stock and custom abutments in either the first or second removal torque values and also no significant difference among initial tightening torque, first or second removal torque (P > 0.05). CONCLUSION: With precise control of CAD/CAM abutments, good screw joint stability can be achieved.

In Vitro Osteogenic Differentiation Enhanced by Zirconia Coated with Nano-Layered Growth and Differentiation Factor-5.

Zirconia (Zr) is also known as a biocompatible material with favorable mechanical properties as well as low plaque adhesion. In this study, we examined the efficacy of Zr coated with growth and differentiation factor-5 (GDF-5) bonded via click reaction as a substrate to support osteogenic differentiation of MC3T3-E1 cells. Pristine and surface-modified Zr surfaces were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), resulting that GDF-5 was successfully coated to the pristine Zr surface. GDF-5 coated to Zr surfaces was released for 28 days in a sustained manner. New bone formation onto GDF-5 coated Zr (Zr/GDF-5) surface was confirmed by in vitro test including cell proliferation, alkaline phosphatase activity and calcium deposition assays, and in vivo test including real-time polymerase chain reaction (qPCR) assay including osterix (OSX), runt-related transcription factor 2 (Runx 2), COL 1 (type I collagen) and osteocalcin (OC). Cell proliferation, alkaline phosphatase activity, and calcium deposition of MC3T3- E1 cells were significantly enhanced when the cells were cultured on Zr/GDF-5. Additionally, the results of qPCR revealed that genes related with osteogenic differentiation were up regulated when the cells were cultured on Zr/GDF-5. Our findings demonstrate that Zr/GDF-5 could be used as a material for enhancing the efficacy of osteogenic differentiation.

Fabricating a tooth- and implant-supported maxillary obturator for a patient after maxillectomy with computer-guided surgery and CAD/CAM technology: A clinical report.

An obturator prosthesis with insufficient retention and support may be improved with implant placement. However, implant surgery in patients after maxillary tumor resection can be complicated because of limited visibility and anatomic complexity. Therefore, computer-guided surgery can be advantageous even for experienced surgeons. In this clinical report, the use of computer-guided surgery is described for implant placement using a bone-supported surgical template for a patient with maxillary defects. The prosthetic procedure was facilitated and simplified by using computer-aided design/computer-aided manufacture (CAD/CAM) technology. Oral function and phonetics were restored using a tooth- and implant-supported obturator prosthesis. No clinical symptoms and no radiographic signs of significant bone loss around the implants were found at a 3-year follow-up. The treatment approach presented here can be a viable option for patients with insufficient remaining zygomatic bone after a hemimaxillectomy.