China ; Dental Prosthesis ; Humans ; Tooth Loss ; surgery

OBJECTIVEAfter sinboneHT bone replacement (SBR) was implanted in animals, to evaluate the biocompatibility of SBR and compounded in autogenetic bone in the proportion of one to one in order to prepare for the clinical applications in the future.

METHODSBone defects of 10 mm x l0 mm x 2 mm was made at the mandibular of rabbits, then SBR with different granule diameter and autogenetic bone was compounded in the proportion of being applied in the left defects, while autogenetic bone was implanted in the right defects and nothing was used in the right reformed defects. Animals were sacrificed at 2, 4 and 8 weeks respectively. The biologic capacity was evaluated with anatomy, X-rays studies and histology.

RESULTSSBR has better biocompatibility, which can effectively accelerate the reconstruction of bone defects and help the new bone by being compounded with autogenetic bone. It provides the appropriate scaffold or template which would allow cellular infiltration, attachment and multiplication.

CONCLUSIONSBR is a kind of bone substitute material with good biocompatibility. SBR compounded with self-bone has a better regeneration function.

Animals ; Bone Regeneration ; Bone Substitutes ; Mandible ; Rabbits ; Reconstructive Surgical Procedures

OBJECTIVETo prepare zirconia toughened nano-composite alumina ceramic powder for dental application. Physical and chemical property of the prepared material were tested, and the effect of development technology on composite powder was also studied in this study.

METHODSNano-composite alumina powder was prepared by surface-induced precipitation method. The effect of pH value and dispersing agent content on volume of alumina suspension sediment was recorded. The effect of ultrasonic time on agglomeration was measured also. X ray diffraction (XRD) was used to analyze powder phase before and after the stabilizer was added. Scanning electronic microscope (SEM) was applied for characterizing the specimen.

RESULTSThe dispersion was better at pH=9 and wt (dispersing agent) = 0.2% approximately 0.3%. Selecting proper ultrasonic time can decrease the agglomeration of powders and lower the average particle size. XRD analysis indicated that the phase composition of the prepared nano-composite ceramic powder was shown as alpha-Al2O3, t-ZrO2 and a small amount of m-ZrO2 after the addition of stabilizer. Through SEM observation, nanometer-sized ZrO2 particles (80 approximately 100 nm) were uniformly located on the surface of submicrometer alumina grains.

CONCLUSIONSBy choosing appropriate preparation method, weakly agglomerated powders with fine particle size can be obtained. The zirconia part of nano-composite powder was transmitted to partially stabled zirconia after the use of stabilizer.

Aluminum Oxide ; chemistry ; Dental Porcelain ; chemistry ; Hydrogen-Ion Concentration ; Powders ; Zirconium ; chemistry

OBJECTIVETo study the distribution of the chromatic value of gingival porcelains.

METHODSThe color change of Shofu VINTAGE and Vita VMK95 gingival porcelains on the black and white backings was determined with a spectrophotometer (PR-650).

RESULTSThe results showed that the chromatic value of gingival porcelains was different on varying backings. The color space of gingival porcelain was L*: 41.85 - 50.64, a*: 12.46 - 19.46, b*: 1.33 - 4.62.

CONCLUSIONThe chromatic value distribution cannot cover the color region of natural gingiva.

Color ; Dental Porcelain ; Gingiva ; Spectrophotometry

OBJECTIVEThe purpose of this study was to evaluate the color changes of gingival porcelain through varying thickness and shade of porcelain of ceramometal restorations.

METHODSIn this study a spectrophotometer (PR-650) was used for color analysis. The color changes of dentin porcelain and gingival porcelain with three varied thickness (0.3 mm, 0.6 mm and 0.9 mm) were investigated. In addition, the color variances of Shofu vintage porcelain shade A2, A3 and B2 were tested.

RESULTSThe results showed that decreased L * value of ceramometal restorations and increased a * value were due to the increase of the gingival porcelain thickness, color measurements showed the same trend as the increased dentin porcelain thickness and the opaque and dentin porcelain with different color affected the appearance of gingival porcelain.

CONCLUSIONThe color of gingival porcelain would be changed with the differences of thickness and shade of porcelain of ceramometal restorations.

Color ; Dental Porcelain ; Humans ; Prosthesis Coloring ; Spectrophotometry

OBJECTIVETo study the influence of manufacture technique on the translucency and color of dental porcelain.

METHODSSpecimens were made of VITA VMK 95 dentin porcelain and enamel porcelain and divided into 3 groups: Sintering times group (1, 2, 4, 6, 8 and 10 times), sintering temperature group (910, 920, 930, 940 and 950 degrees C), sintering vacuum group (95, 65, 35 and 0 kPa). Transmittance, Y, dominant wavelength and saturation were measured by PR-650 spectra scan spectrocolorimeter.

RESULTSTransmittance of dentin porcelain increased after 6 times repeated sintering. Transmittance of enamel porcelain increased first after the second sintering, and then became decreasing when sintering more than 2 times. Transmittance of enamel porcelain deceased when sintering temperature was lower than standard. Decrease of sintering vacuum caused the transmittance of dentin and enamel porcelain decreased. The changing of value was coordinated with transmittance. Dominant wavelength and saturation had negative correlation with sintering times and temperature, and positive correlation with vacuum.

CONCLUSIONSintering times, temperature and vacuum all had prominent effects on the translucency and color of dental porcelain. Comparing with dentin porcelain, enamel porcelain was more sensitive with the modification of manufacture technique.

Color ; Dental Alloys ; Dental Enamel ; Dental Porcelain ; Dentin ; Humans ; Temperature

OBJECTIVETo get aesthetic implant-supported restorations by means of the all-ceramic crown fused to small-size titanium abutment and evaluate the quality of the restorations.

METHODSA small-size titanium abutment that had extremely thin circumferential collar and axial wall was fabricated, while a Cercon all-ceramic crown made with computer aided manufacture (CAM). The crown was fused to the abutment by firing the opaque porcelain. A total of 6 restorations in 5 patients were installed and assessed according to the California Dental Association (CDA) quality evaluation system.

RESULTSAll the restorations were fabricated well and ranked in clinic evaluation excellent for surface, anatomical form, marginal quality, and color at baseline and one year after insertion, respectively.

CONCLUSIONSThe restoration of all-ceramic crown fused to titanium small-size abutment is a new aesthetic alternative for the implant-supported restoration.

Adult ; Crowns ; Dental Abutments ; Dental Implants, Single-Tooth ; Dental Porcelain ; Dental Prosthesis Design ; Dental Prosthesis, Implant-Supported ; methods ; Female ; Humans ; Male ; Titanium

OBJECTIVETo investigate the effect of a new engineering technique of vacuum deposition-plasma magnetron reactive sputter deposition technique on the metal-porcelain bond strength of a new type of Co-Cr ceramic and framework dental alloy.

METHODSBefore porcelain painted on the specimens, the standardized metal strips made from DA9-4 dental alloy were coated with a thin Al2O3 ceramic film by plasma magnetron reactive sputter deposition technique. The conformation, structure and thickness of the ceramic film were analyzed. The specimens for three-point bending test made from DA9-4 alloy and VMK95 porcelain were used for metal-porcelain bond strength measurement, in the same time the interface of metal-porcelain and element distribution were also observed.

RESULTSThe flexural bonding strength of metal-porcelain of sputtering group and control group were (180.55+/-16.45) MPa and (143.80+/-24.49) MPa. The flexural bonding strength of metal-porcelain of sputtering group was higher than control group significantly through statistical analysis (P<0.01).

CONCLUSIONThe plasma magnetron reactive sputter deposition technique has a positive effect in improving the bonding strength of DA9-4 dental alloy and ceramic.

Ceramics ; Chromium Alloys ; Dental Alloys ; Dental Bonding ; Dental Porcelain ; Humans ; Materials Testing ; Metal Ceramic Alloys ; Surface Properties ; Vacuum

OBJECTIVETo investigate the effects of the static magnetic field (SMF) generated by dental magnetic attachments on osteoblastic proliferations, cell cycle distribution, and apoptosis ratio.

METHODSBy simulating those of the closed-field, the closure process and the open-field Magnedisc 800 magnetic attachments respectively, the in vitro cultured rat osteoblasts were exposed continuously to 12.5, 125, 250 mT SMF. The effects of the SMF on the proliferation of the cells were examined. MTT colorimetry test was performed to detect the effect of the SMF on the vitalities of cells. Flow cytometry was utilized to analyze the cell cycles and cell apoptosis rates.

RESULTSThe SMF exposure didn't change the vital osteoblasts number, the cell cycle distribution and proliferation activities of osteoblasts. The cell apoptosis situation were not observed statistical differences.

CONCLUSIONNo matter the closed-field, the closure process and the open-field magnetic attachments respectively, continuous simulating SMF-stimulation of magnetic attachments couldn't change osteoblasts proliferation activity, cell cycle distribution, and apoptosis ratio.

Animals ; Apoptosis ; Cell Cycle ; Cell Proliferation ; Electromagnetic Fields ; Magnetic Fields ; Magnetic Phenomena ; Magnetics ; Osteoblasts ; Rats

OBJECTIVETo evaluate the biologic effects of simulating static magnetic field of magnetic attachment on human periodontal ligament fibroblasts (HPDLF).

METHODSHPDLF were cultured in vitro and exposed to simulating static magnetic fields of magnetic attachments for 4 days with magnetic flux density of 12.5, 125 and 250 mT respectively, while the control group free of additional static magnetic field was also set up. The activities of cellular alkaline phosphatase (ALP) and superoxide dismutase (SOD) were measured with a spectrophotometer, and cell cycle was analyzed by flow cytometry.

RESULTSAn increase were detected, induced by 250 mT static magnetic field exposure for 4 days in terms of activity of ALP in HPDLF, as compared with the control group (P < 0.05). However, no corresponding effects were found in activity measurements of SOD (P > 0.05). Also there were no statistical differences observed on cell cycle distribution (P > 0.05) or cell proliferation index (P > 0.05) under such static magnetic fields.

CONCLUSIONThe static magnetic fields of magnetic attachment used in this study have improved the activity of ALP, and do little inference to the activity of SOD and the cell cycle distribution.

Alkaline Phosphatase ; Biological Products ; Cell Proliferation ; Fibroblasts ; Humans ; Magnetic Fields ; Magnetic Phenomena ; Magnetics ; Periodontal Ligament