Use of a digitally guided triple technique for bone reduction, implant placement, and immediate interim prostheses in complete-arch implant surgery.

A digitally guided triple technique for bone reduction, implant placement, and immediate interim prostheses in complete-arch implant surgery is presented. This technique integrates bone reduction and implant placement information into a dual-function surgical template and introduces a digital approach to fabricating immediate interim implant-supported fixed dental prostheses with the same occlusal relationship as the one evaluated with diagnostic removable prostheses.

Polyetheretherketone versus titanium CAD-CAM framework for implant-supported fixed complete dentures: a retrospective study with up to 5-year follow-up.

PURPOSE: To evaluate the performance of polyetheretherketone (PEEK) versus titanium computer-aided designed and manufactured (CAD-CAM) framework for implant-supported fixed complete dentures (ISFCDs) with a follow-up for a duration of up to 5 years. METHODS: Consecutively edentulous patients who underwent ISFCDs with a PEEK framework or titanium framework at one dental specialist center were included in this retrospective study. Implant/prosthesis survival rates, mechanical/biological complications, and bone and soft tissue parameters were analyzed. Overall survival was analyzed using Kaplan-Meier survival curves and the log-rank test. RESULTS: Sixty ISFCDs (29 PEEK, 31 titanium) performed on 43 edentulous patients (331 implants) were included. An implant survival rate of 100% was obtained. There was no significant difference in the cumulative prosthesis survival rate between the PEEK (93.1%) and titanium groups (93.5%). The most common mechanical complications were fracture of the artificial veneer in both the PEEK (13.8%) and titanium (16.7%) groups. Bruxers had a higher prevalence of mechanical complications than non-bruxers (p<0.05). The biological complications included bleeding upon probing (13.8% for the PEEK group; 16.1% for the titanium group), soft tissue inflammation (3.4% for the PEEK group; 3.2% for the titanium group), and temporomandibular disorders (6.5% for the titanium group). The vertical bone loss was significantly lower in the PEEK group (0.70 mm) than in the titanium group (0.96 mm). Smokers had a significantly higher prevalence of biological complications than non-smokers. CONCLUSION: Within the limitations of this study, ISFCDs with PEEK frameworks can provide good prognosis for edentulous patients, still requiring longer-term validation.

Antibacterial Peptide HHC-36 Sustained-Release Coating Promotes Antibacterial Property of Percutaneous Implant.

Percutaneous implants are widely used in clinical practice. However, infection is the main clinical problem of percutaneous implants. Titanium dioxide nanotubes are suitable for forming coatings on complex surfaces such as implants. HHC-36, a cationic antimicrobial peptide, has been identified to have a strong broad-spectrum antibacterial effect. In the present study, we use poly D,L-lactic acid (PDLLA) and poly lactic-co-glycolic acid (PLGA) coating to build HHC-36 sustained-release system on the surface of titanium dioxide nanotubes. The titanium specimens were anodized coated with HHC-36-PDLLA/PLGA. The morphology and surface elemental distribution of the specimens were evaluated. Besides, results in the present study demonstrated that with antibacterial peptide HHC-36 sustained-release coating, titanium dioxide nanotubes maintain effective drug release for 15 days in vitro, and show significant antibacterial activity. The proliferation of Staphylococcus aureus can be effectively inhibited by PDLLA/PLGA-HHC-36 coated titanium dioxide nanotube. In addition, PDLLA-HHC-36 and PLGA-HHC-36 coating was demonstrated to be biocompatible and antibacterial in vivo. These findings demonstrated that HHC-36 coated titanium nanotube could improve antibacterial potential of percutaneous implants, and indicated a novel and efficient strategy in preventing bacterial infection of percutaneous implants.

Clinical outcomes of implant-retained mandibular overdentures using the bar and magnetic attachment systems: an up to 5-year retrospective study.

BACKGROUND: Implant-retained mandibular overdentures (IODs) represent an effective and reliable treatment modality for edentulous patients. The present retrospective study compared the clinical outcomes of IODs using bar attachment (BA) system with those using magnetic attachment (MA) system after functioning for up to 5 years. METHODS: Human subjects treated with IODs between 01-01-2010 and 12-31-2014 were identified from patient records. Of the 54 subjects who met the inclusion criteria, 48 subjects including 26 treated with BA-IODs and 22 with MA-IODs (96 mandibular implants) were recruited for the study. The implant units and prostheses were evaluated individually for peri-implant health. Prosthetic complications and maintenance during follow-up were recorded. The subjects responded to the visual analog scale (VAS) and the Oral Health Impact Profile questionnaires for evaluation of patient satisfaction and oral health-related quality of life (OHRQoL). RESULTS: The survival rates of the implants and prostheses were 96.9% and 95.8%, respectively, over a mean observation period of 48±11.3 (range, 13-64) months. Peri-implant probing depth (PPD) and plaque index (PI) were significantly better for the MA group compared with the BA group (P<0.05), while marginal bone loss (MBL) and sulcus bleeding index (SBI) showed no significant differences (P>0.05). Prosthetic complications and maintenance were attachment-dependent. Most recruited subjects were satisfied with their prostheses. There was no statistically significant difference regarding general patient satisfaction or OHRQoL between the two groups (P>0.05). Nevertheless, patients complained that the BA-IODs were significantly more difficult to clean than the MA-IODs (P<0.05). CONCLUSIONS: IODs have an ideal medium-term outcome irrespective of the attachment design. It is recommended that oral hygiene instructions and regular clinical examination be given to subjects wearing IODs.

[Minimal invasive microscopic tooth preparation based on endodontic, periodontal and functional health].

Tooth preparation is the primary and core operation technique for dental esthetic restoration treatment, due to its effect of providing restoration space, bonding interfaces and marginal lines for dental rehabilitation after tooth tissue reduction. The concept of microscopic minimal invasive dentistry put forward the issue of conducting high-quality tooth preparation, conserve tooth-structure, protect vital pulp and periodontal tissue simultaneously. This study reviewed the concepts, physiology background, design and minimal invasive microscopic tooth preparation, and in the meantime, individualized strategies and the two core elements of tooth preparation (quantity and shape) are listed.

Intrafibrillar silicified collagen scaffold promotes in-situ bone regeneration by activating the monocyte p38 signaling pathway.

Intrafibrillar silicified collagen scaffold (SCS) is a promising biomaterial for bone regeneration because it promotes cell homing and angiogenesis in bone defects via monocyte modulation. In the present study, a rat femoral defect model was used to examine the contribution of monocyte signaling pathways to SCS modulation. Activation of the monocyte p38 signaling pathway by SCS resulted in monocyte differentiation into TRAP-positive mononuclear cells. These cells demonstrated increased secretion of SDF-1α, VEGFa and PDGF-BB, which, in turn, promoted homing of bone marrow stromal cells (BMSCs) and endothelial progenitor cells (EPCs), as well as local vascularization. Monocyte differentiation and secretion were blocked after inhibition of the p38 pathway, which resulted in reduction in cell homing and angiogenesis. Taken together, these novel findings indicate that the p38 signaling pathway is crucial in SCS-modulated monocyte differentiation and secretion, which has a direct impact on SCS-induced bone regeneration. STATEMENT OF SIGNIFICANCE: Intrafibrillar silicified collagen scaffold (SCS) is a promising biomaterial for bone regeneration. The present work demonstrates that SCS possesses favorable bone regeneration potential in a rat femoral defect model. The degrading scaffold modulates monocyte differentiation and release of certain cytokines to recruit MSCs and EPCs, as well as enhances local vascularization by activating the p38 MAPK signaling pathway. These findings indicate that SCS contributes to bone defect regeneration by stimulating host cell homing and promoting local angiogenesis and osteogenesis without the need for loading cytokines or xenogenous stem cells.

[An 8-year follow-up study of Cerec2 computer aided design and computer aided manufacture of all-ceramic crowns].

OBJECTIVE: To evaluate the clinical performance of the crowns made by Cerec2 computer aided design and computer aided manufacture (CAD/CAM) system. METHODS: Twenty four teeth were restored with Cerec2 CAD/CAM crowns. Eight years after delivery of the prostheses, the all-ceramic crowns were evaluated using modified standard of California Dental Association quality evaluation system. Patients filled out a satisfaction questionnaire at the same time. And Kaplan-Meier analysis was carried out. RESULTS: Three out of 24 restorations were rated as failure. Kaplan-Meier analysis showed that the success rate of Cerec2 crowns eight year following delivery was 88%. CONCLUSIONS: Crowns made by Cerec2 CAD/CAM system can survive in oral condition and function well for 8 years.

[The study on fabrication of dental restoration using PMMA-ZrO2 composites via CAD/CAM].

OBJECTIVE: To obtain dental restorations by machining PMMA-ZrO2 organic-inorganic composites with the dental CAD/CAM system. METHODS: Partially sintered Zirconia compacts (PSZC) were prepared via isostatic pressing and partially sintering, with Zirconia nanopowder as raw materials. PMMA-Zirconia organic-inorganic composites were prepared by vacuum infiltrating the prepolymerized MMA into the PSZC, followed by in-situ polymerization. The mechanical properties and machinability of composites were studied. The composites were machined on the dental CAD/CAM system to obtain dental restoration. RESULTS: At 71.44% TD of PSZC, the composite had a 3-point bending strength of (202.56 +/- 3.09) MPa, fracture toughness of (4.30 +/- 0.16) MPa.m(1/2), elasticity modulus of (58.71 +/- 1.98) GPa, and Vickers hardness of (3.82 +/- 0.34) GPa, respectively. A premolar crown was fabricated by CAD/CAM system in 16 mins, and was verisimilitude, without any cracks. CONCLUSIONS: The composite at 71.44% TD of PSZC has good mechanical properties and dental restorations can be manufactured by PMMA-Zirconia composites via dental CAD/CAM system.

[Modification of titanium surface with calcium and phosphorus ions using micro-arc oxidation and its effect on osteoblast attachment].

OBJECTIVE: To study the method for modifying titanium surface with calcium and phosphorus ions using micro-arc oxidation technique and observe osteoblast attachment to the modified surface. METHODS: TA(2) titanium discs were treated with micro-arc oxidation in electrolyte solution containing Ca(2+) and PO(4)(3-). The influence of Ca(2+) and PO(4)(3-) concentrations in the solution and the electrical parameters of the micro-arc oxidization on the content of calcium and phosphorus ions incorporated into the surface of titanium was investigated using energy-dispersive X-ray (EDX) analysis. Scanning electron microscopy was employed for morphological observation of the ceramic coating on the metal surface. The binding strength of ceramic coating with titanium was tested by shear bonding experiment. MC-3T3-E1 osteoblast-like cells were then cultured on the treated surface of titanium discs to investigate the influence of the ceramic coating on osteoblast attachment. RESULTS: Micro-arc oxidation treatment produced a layer of porous TiO(2) coating on the surface of titanium discs, with the average pore size of 2 to 10 mum. EDX analysis revealed that the ceramic coating contained Ca and P elements, whose content had close correlation with Ca(2+) and PO(4)(3-) concentrations in the electrolyte solution and voltage, duty cycle and frequency of micro-arc oxidation. The average bonding strength of the ceramic coating with titanium was 22+/-3 MPa, and TiO(2) coating promoted attachment and spread of osteoblast-like cells on the metal surface as demonstrated by cell culture. CONCLUSIONS: Porous TiO(2) coating can be constructed on the surface of titanium using micro-arc oxidation, and Ca(2+) and PO(4)(3-) incorporated into the coating can improve the biocompatibility of titanium. The content of Ca(2+) and PO(4)(3-) in the coating can be modulated by adjusting the concentrations of Ca(2+) and PO(4)(3-) in the electrolyte solution and the electrical parameters of the micro-arc oxidation.

[Influence of eugenol-containing temporary cement on efficacy of dentin-bonding systems].

OBJECTIVE: This study investigated the influence of eugenol-containing temporary cement on the efficacy of two relatively new dentin-bonding systems. METHODS: Thirty-two freshly extracted bovine central incisors were randomly divided into four groups. Dentin was exposed and polished with 320#, 400#, and 600# sand papers. After embedded, Group 3 and 4 specimens were covered with ZOE. Specimens in Group 1 and 2 were served as control. All specimens were stored for 1 week in distilled water at 37 degrees C. Then, the ZOE was mechanically removed. The dentin surfaces of Group 1 and 3 were treated with Prime & Bond NT bonding system and the dentin surfaces of Group 2 and 4 were treated with GLUMA adhesive system according to manufacturer's instructions. Thereafter composite resin columns (6 mm diameter, 2 mm high) were applied. After specimens stored in distilled water at 37 degrees C for 24 hours, the shear bond testing was carried out using a SHIMADZU universal testing machine with a cross-head speed of 0.5 mm/minute. The mode of failure was examined using SEM. The data were analyzed using ANOVA test at a significance level of 0.05. RESULTS: The medians of shear bond strength for each group were as follows: Group 1 (Prime & Bond NT) 9.57 MPa, Group 3 (Prime & Bond NT + ZOE) 10.72 MPa, Group 2 (GLUMA) 16.89 MPa, Group 4 (GLUMA + ZOE) 16.78 MPa. Group 1 and 3 had significantly lower bonding strength than did Groups 2 and 4. But no significant difference was found between the control groups and the groups treated with ZOE temporary cement. CONCLUSION: Pretreatment of the dentin with ZOE temporary cement has no adverse influence on the efficacy of two relatively new dentin-bonding systems.