Mineral trioxide aggregate (MTA) was developed in early 1990s and has been successfully used for root perforation repair, root end filling, and one-visit apexification. MTA is composed mainly of tricalcium silicate and dicalcium silicate. When MTA is hydrated, calcium silicate hydrate (CSH) and calcium hydroxide is formed. Formed calcium hydroxide interacts with the phosphate ion in body fluid and form amorphous calcium phosphate (ACP) which finally transforms into calcium deficient hydroxyapatite (CDHA). These mineral precipitate were reported to form the MTA-dentin interfacial layer which enhances the sealing ability of MTA. Clinically, the use of zinc oxide euginol (ZOE) based materials may retard the setting of MTA. Also, the use of acids or contact with excessive blood should be avoided before complete set of MTA, because these conditions could adversely affect the hydration reaction of MTA. Further studies on the chemical nature of MTA hydration reaction are needed.
Aluminum Compounds ; Apexification ; Body Fluids ; Calcium ; Calcium Compounds ; Calcium Hydroxide ; Calcium Phosphates ; Drug Combinations ; Durapatite ; Glutamates ; Guanine ; Hydroxides ; Oxides ; Silicates ; Silicic Acid ; Zinc Oxide ; Pemetrexed

OBJECTIVETo observe the expression of inducible nitric oxide synthase (iNOS) in rat dental pulp after direct pulp capping with calcium hydroxide (CH) and mineral trioxide aggregate (MTA).

METHODSSamples from 42 Wistar rats were immediately collected at 1, 3, 7, 14, 21 and 28 days after direct pulp capping with CH and MTA. Pulp tissues were studided with immunohistochemical stain. Software for image analysis was used to test the optical density of each specimen. The data were analyzed by paired t-test and Dunnett-t test with SPSS 11.5.

RESULTSIn normal pulp, the stain of iNOS was negative. After direct pulp capping with CH or MTA, iNOS expression demonstrated weakly positive, positive, weakly positive, negative at different time, the expression was low immediately after capping but became strong after 3 days. Until 7 days the stain became less positive gradually and at 21 days the stain approached normal. The expression was mainly at the fibroblasts, odontoblasts, vascular endothelial cells, neutrophils, etc near the bottom of the pulp capping agent. The diffence of iNOS expression was significant 3 days after direct pulp capping with this two capping agents.

CONCLUSIONAfter direct pulp capping, iNOS expression increasd at first and then decreased, the diffence of capping agents will have an impact on the expression of iNOS 3 days after direct pulp capping.

Aluminum Compounds ; Animals ; Calcium Compounds ; Calcium Hydroxide ; Dental Pulp ; Dental Pulp Capping ; Drug Combinations ; Nitric Oxide Synthase Type II ; Oxides ; Pulp Capping and Pulpectomy Agents ; Rats ; Rats, Wistar ; Root Canal Therapy ; Silicates

The aim of this study was to compare the compositions and cytotoxicity of white ProRoot MTA (white mineral trioxide aggregate) and 3 kinds of Portland cements. The elements, simple oxides and phase compositions of white MTA (WMTA), gray Portland cement (GPC), white Portland cement (WPC) and fast setting cement (FSC) were measured by inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray fluorescence spectrometry (XRF) and X-ray diffractometry (XRD). Agar diffusion test was carried out to evaluate the cytotoxicity of WMTA and 3 kinds of Portland cements. The results showed that WMTA and WPC contained far less magnesium (Mg), iron (Fe), manganese (Mn), and zinc (Zn) than GPC and FSC. FSC contained far more aluminum oxide (Al2O3) than WMTA, GPC, and WPC. WMTA, GPC, WPC and FSC were composed of main phases, such as tricalcicium silicate (3CaO.SiO2), dicalcium silicate (2CaO.SiO2), tricalcium aluminate (3CaO.Al2O3), and tetracalcium aluminoferrite (4CaO.Al2O3.Fe2O3). The significance of the differences in cellular response between WMTA, GPC, WPC and FSC was statistically analyzed by Kruskal-Wallis Exact test with Bonferroni's correction. The result showed no statistically significant difference (p > 0.05). WMTA, GPC, WPC and FSC showed similar compositions. However there were notable differences in the content of minor elements, such as aluminum (Al), magnesium, iron, manganese, and zinc. These differences might influence the physical properties of cements.
Agar ; Aluminum ; Aluminum Oxide ; Calcium Compounds ; Diffusion ; Glutamates ; Guanine ; Humans ; Iron ; Magnesium ; Manganese ; Oxides ; Plasma ; Silicates ; Spectrometry, X-Ray Emission ; Spectrum Analysis ; Zinc ; Pemetrexed

OBJECTIVETo evaluate the clinical prosthetic effect of IPS-Empress 2 pressahie ceramic crowns.

METHODS198 teeth of 70 patients were restored with IPS-Empress 2 pressahie ceramic crowns. The patients were asked to return in one week and every half year. The clinical prosthetic effect was evaluated.

RESULTSThrough follow-up of 3-38 months, the veneer porcelain crowns of 3 teeth were broken. 2 crowns fall off due to teeth fracture, gingivitis occurred in 2 teeth, pulpitis or periapical periodontitis occurred in 3 teeth. The shades of 3 crowns were darkening. The prosthetic effect of 185 teeth was satisfied. The rate of satisfaction was 93.4%.

CONCLUSIONIPS-Empress 2 pressable all-ceramic crown has the advantages of aesthetic effect, good hiocompatihility and simple fabrication. But its strength is not enough for posterior teeth and it can not cover the deep color of non-vital teeth and metal materials.

Aluminum Silicates ; Ceramics ; Crowns ; Dental Porcelain ; Humans ; Lithium Compounds

This study was carried out in order to determine in vitro biocompatibility of white mineral trioxide aggregate (MTA), and to compare it with that of the commonly used materials, i. e. calcium hydroxide liner (Dycal), glass ionomer cement (GIC), and Portland cement which has a similar composition of MTA. To assess the biocompatibility of each material, cytotoxicity was examined using MG-63 cells. The degree of cytotoxicity was evaluated by scanning electron microscopy (SEM) and a colorimetric method, based on reduction of the tetrazolium salt 2,3 bis {2methoxy 4nitro 5[(sulfenylamino) carbonyl] 2H tetrazolium hydroxide} (XTT) assay. The results of SEM revealed the cells in contact with GIC, MTA, and Portland cement at 1 and 3 days were apparently healthy. In contrast, cells in the presence of Dycal appeared rounded and detached. In XTT assay, the cellular activities of the cells incubated with all the test materials except Dycal were similar, which corresponded with the SEM observation. The present study supports the view that MTA is a very biocompatible root perforation repair material. It also suggests that cellular response of Portland cement and GIC are very similar to that of MTA.
Acrylic Resins ; Aluminum Compounds ; Calcium Compounds ; Calcium Hydroxide ; Drug Combinations ; Glass Ionomer Cements ; Glutamates ; Guanine ; Humans ; Hydroxides ; Microscopy, Electron, Scanning ; Minerals ; Oxides ; Silicates ; Silicon Dioxide ; Pemetrexed

OBJECTIVEThis study aims to investigate the effects of mineral trioxide aggregate (MTA) and calcium hydroxide on proliferation and differentiation of human pulp cells from primary and permanent teeth.

METHODSCell proliferation was detected by methyl thiazolyl tetrazolium (MTT) assay. The mRNA expression levels of dentinogenesis-related factors, including alkaline phosphatase (ALP) and dentin sialophosphoprotein (DSPP), and odontoclastogenesis-related factors, such as osteo- protegerin (OPG) and receptor activator of NF-κB ligand (RANKL), were determined by real time polymerase chain reac- tion (PCR).

RESULTSPrimary and permanent pulp cells treated with calcium hydroxide exhibited significantly lower proli- feration rates than the control cells (P<0.01). By contrast, the MTA-treated group showed significantly higher proliferation rates than the control group (P<0.01). Real time PCR results showed that calcium hydroxide-treated primary pulp cells exhi- bited significantly decreased ALP, DSPP, and OPG expression compared with the control group (P<0.01). Conversely, the MTA-treated group displayed significantly increased ALP, DSPP, and OPG expression (P<0.01). Calcium hydroxide-treated primary pulp cells also exhibited significantly upregulated RANKL expression (P < 0.01); by contrast, MTA-treated cells did not show any change in RANKL expression (P>0.05). Likewise, MTA-treated permanent pulp cells showed significantly upregulated ALP and DSPP expression (P < 0.01). However, the calcium hydroxide-treated group remained almost the same as the control group (P > 0.05). Neither MTA nor calcium hydroxide affected OPG and RANKL expression in per- manent pulp cells (P > 0.05).

CONCLUSIONMTA is more suitable as a pulp-capping agent, particularly in primary teeth, than calcium hydroxide.

Aluminum Compounds ; Calcium Compounds ; Calcium Hydroxide ; Cell Differentiation ; Cell Proliferation ; Dental Pulp ; Dentition, Permanent ; Drug Combinations ; Extracellular Matrix Proteins ; Humans ; Oxides ; Phosphoproteins ; Sialoglycoproteins ; Silicates

OBJECTIVETo evaluate the clinical effect of treatment of open apices teeth with mineral trioxide aggregate (MTA) compared with apexification using Vitapex in the adult.

METHODSThe root canals of 41 anterior teeth and premolars with single canal and open apices in adults were cleaned and shaped, and then disinfected with calcium hydroxide. The apical root canals of 21 teeth in experimental group were filled with MTA to create a 3-5 mm apical barrier. The remainder of the canals was filled with AH plus and Obtura II gutta-percha. The canals of 20 teeth in control were treated with Vitapex. The root canals were then filled with Obtura II gutta-percha when the apical barrier could be detected. The visit times, period and result of the treatment were recorded for all cases.

RESULTSGood result was achieved in the most cases in the experimental group. The postoperative X-ray films showed that the canals of 15 teeth were obturated well. 6 teeth showed over-filling by 0.5-2 mm. The recalled patients declared their teeth to be asymptomatic except one. The recall radiographs indicated that the apical radiolucent areas of the teeth with pre-existing apical lesion decreased apparently or disappeared completely, except one tooth with large apical radiolucency. No new radiolucency was found around the roots. In the control group, the apexification of 11 teeth succeeded, and 9 failed. The average visit times was 3.5 in experimental group and 6.0 in control. The average period of the whole endodontic treatment was 11.8 days in experimental group and 306.8 in control.

CONCLUSIONMTA is more effective and quicker than apexification in treatment of teeth with open apices in adults.

Adult ; Aluminum Compounds ; Calcium Compounds ; Calcium Hydroxide ; Drug Combinations ; Gutta-Percha ; Humans ; Oxides ; Root Canal Filling Materials ; Silicates ; Silicones ; Tooth Apex

The long-term effect of direct pulp capping and pulpotomy is closely related to the type of pulp capping materials. Various kinds of direct pulp capping materials are available, such as calcium hydroxide and mineral trioxide aggregates. Diverse new pulp capping materials have been reported recently. The excellent performance of calcium silicates has attracted much attention in previous studies. Moreover, enamel matrix derivative (Emdogain), which is capable of regeneration and remineralization, and other materials with similar capabilities have shown potential for use in pulp capping.
Aluminum Compounds ; Calcium Compounds ; Calcium Hydroxide ; Dental Pulp ; Dental Pulp Capping ; Drug Combinations ; Oxides ; Pulp Capping and Pulpectomy Agents ; Pulpotomy ; Root Canal Therapy ; Silicates

PURPOSE: The purposes of this study were to investigate osseointegration around zirconia implants which had machined or alumina sandblasted surface, and to compare the results with titanium implants. MATERIALS AND METHODS: The study was performed on the tibia of 6 pigs. Three types of implants were investigated: group T-titanium implant, group Z-machined zirconia implant, group ZS-alumina sandblasting treated zirconia implant. Zirconia implants were manufactured from yttria-stabilized tetragonal zirconia polycrystalline (Acucera Inc., Pocheon, Korea). A total of 36 implants were installed in pigs' tibias. After 1, 4 and 12 weeks of healing period, the periotest and the histomorphometric analysis were performed. The data were analyzed using one-way ANOVA and significance was assessed by the Scheffe test (alpha=.05). RESULTS: In the measurement of surface roughness, highest Ra value was measured in group T with significant difference. No significant differences were found among groups regarding Periotest values. After 1 week, in comparison of bone to implant contact (BIC), group Z showed higher value with significant difference. In comparison of bone area (BA), group T and group Z showed higher value with significant difference than group ZS. After 4 weeks, in comparison of BIC, group T showed higher value with significant difference. Comparison of BA showed no significant difference among each implant. After 12 weeks, the highest mean BIC values were found in group T with significant difference. Group ZS showed higher BIC value with significant difference than group Z. In comparison of BA, group T and group ZS showed higher value with significant difference than group Z. CONCLUSION: Zirconia implant showed low levels of osseointegration in this experiment. Modification of surface structure should be taken into consideration in designing zirconia implants to improve the success rate.
Aluminum Oxide ; Nitrogen Mustard Compounds ; Osseointegration ; Swine ; Tibia ; Titanium ; Zirconium

OBJECTIVETo study the effects of alum, aluminum chloride and aluminum hydroxide on aluminum contents in serum and brain of mice with high performance capillary.

METHOD60 days after the mice were given daily alum, aluminum chloride and aluminum hydroxide with the same aluminum content of 14.25, 57 mg x kg(-1) x d(-1), respectively, the aluminum content in serum and brain of mice were determined with high performance capillary chromatography.

RESULTThe average recoveries of serum aluminum determination was 96.5%-103%. The average recoveries of brain aluminum assay was 92.2%-105.3%. Except control group, serum aluminum increased obviously. Brain aluminum increased in all the large doses groups. 2 weeks after the mice were stopped being given these drugs, serum and brain aluminum recovered to normal level, except aluminum chloride large doses group.

CONCLUSIONThe metabolism and excretion mechanism of aluminum in mice depends on the chemical states of the aluminum compound.

Administration, Oral ; Alum Compounds ; administration & dosage ; pharmacokinetics ; Aluminum ; blood ; metabolism ; Aluminum Compounds ; administration & dosage ; pharmacokinetics ; Aluminum Hydroxide ; administration & dosage ; pharmacokinetics ; Animals ; Brain ; metabolism ; Chlorides ; administration & dosage ; pharmacokinetics ; Electrophoresis, Capillary ; methods ; Male ; Mice