The purpose of this study was to measure the polymerization shrinkage and hygroscopic expansion of resin-based temporary filling materials and to evaluate microleakage at the interface between the materials and cavity wall. Five resin-based temporary filing materials were investigated: Fermit (Vivadent), Quicks (Dentkist), Provifil (Promedica), Spacer (Vericom), Clip (Voco). Caviton (GC) was also included for comparison. Polymerization shrinkage of five resin-based temporary filling materials was measured using the bonded disc method. For the measurement of hygroscopic expansion, the discs of six cured temporary filling materials were immersed in saline and a LVDT displacement sensor was used to measure the expansion for 7 days. For estimating of microleakage, Class I cavities were prepared on 120 extracted human molars and randomly assigned to 6 groups of 20 each. The cavities in each group were filled with six temporary filling materials. All specimens were submitted to 1000 thermo-cycles, with temperature varying from 5degrees C/55degrees C. Microleakage was determined using a dye penetration test. The results were as follows: 1. Fermit had significantly less polymerization shrinkage than the other resin-based temporary filling materials. Fermit (0.22 %) < Spacer (0.38 %) < Quicks (0.64 %), Provifil (0.67 %), Clip (0.67 %) 2. Resin-based temporary filling materials showed 0.43 - 1.1 % expansion in 7 days. 3. Fermit showed the greatest leakage, while Quicks exhibited the least leakage. 4. There are no correlation between polymerization shrinkage or hygroscopic expansion and microleakage of resin-based temporary filling materials.
Calcium Sulfate ; Dental Cements ; Displacement (Psychology) ; Humans ; Molar ; Polymerization ; Polymers ; Polymethacrylic Acids ; Root Canal Filling Materials ; Vinyl Compounds ; Zinc Oxide

OBJECTIVES: The purpose of this study was to evaluate the microleakage of 4 temporary materials in teeth with Class II-type endodontic access preparations by using a glucose penetration model. MATERIALS AND METHODS: Glucose reaction test was performed to rule out the presence of any reaction between glucose and temporary material. Class II-type endodontic access preparations were made in extracted human premolars with a single root (n = 10). Each experimental group was restored with Caviton (GC), Spacer (Vericom), IRM (Dentsply-Caulk), or Fuji II(GC). Microleakage of four materials used as temporary restorative materials was evaluated by using a glucose penetration model. Data were analyzed by the one-way analysis of variance followed by a multiple-comparison Tukey test. The interface between materials and tooth were examined under a scanning electron microscope (SEM). RESULTS: There was no significant reaction between glucose and temporary materials used in this study. Microleakage was significantly lower for Caviton and Spacer than for Fuji II and IRM. SEM observation showed more intimate adaptation of tooth-restoration interfaces in Caviton and Spacer than in IRM and Fuji II. CONCLUSIONS: Compared to IRM and Fuji II, Caviton and Spacer can be considered better temporary sealing materials in Class II-type endodontic access cavities.
Bicuspid ; Calcium Sulfate ; Dental Cements ; Electrons ; Glass Ionomer Cements ; Glucose ; Humans ; Root Canal Filling Materials ; Tooth ; Vinyl Compounds ; Zinc Oxide

The purpose of this study was to compare the sealing abilities of four endodontic temporary restorative materials using a methylene blue dye penetration test under dynamic loading. Standardized access cavities were prepared in forty-four intact human permanent molar teeth, and the cavities were restored with Caviton, MD-Temp, IRM, or ZOE. After thermocycling, an intermittent load of 98 N at 1 Hz was applied for 1,000 cycles to the long axis of the functional cusp of each of the teeth, which were immersed in a 1% methylene blue solution. The teeth were split in half, and the linear depth of dye penetration was evaluated according to the criteria. The results were analyzed using one-way ANOVA (p = 0.05) and Duncan's multiple range test. The results demonstrated that Caviton and MD-Temp showed significantly lower microleakage than IRM and ZOE. It was concluded that Caviton and MD-Temp exhibited better sealing ability than IRM and ZOE under dynamic loading.
Axis, Cervical Vertebra ; Calcium Sulfate ; Dental Cements ; Humans ; Methylene Blue ; Molar ; Root Canal Filling Materials ; Tooth ; Vinyl Compounds ; Zinc Oxide

OBJECTIVES: This in vitro study investigated whether short-term application of calcium hydroxide in the root canal system for 1 and 4 wk affects the fracture strength of human permanent teeth. MATERIALS AND METHODS: Thirty two mature human single rooted mandibular premolars in similar size and dentin thickness without decay or restorations were hand and rotary instrumented and 16 teeth vertically packed with calcium hydroxide paste and sealed coronally with caviton to imitate the endodontic procedure and the other 16 teeth was left empty as a control group. The apicies of all the samples were sealed with resin, submerged in normal saline and put in a storage box at 37degrees C to mimic the oral environment. After 1 and 4 wk, 8 samples out of 16 samples from each group were removed from the storage box and fracture strength test was performed. The maximum load required to fracture the samples was recorded and data were analysed statistically by the two way ANOVA test at 5% significance level. RESULTS: The mean fracture strengths of two groups after 1 wk and 4 wk were similar. The intracanal placement of calcium hydroxide weakened the fracture strength of teeth by 8.2% after 4 wk: an average of 39.23 MPa for no treatment group and 36.01 MPa for CH group. However there was no statistically significant difference between experimental groups and between time intervals. CONCLUSIONS: These results suggest that short term calcium hydroxide application is available during endodontic treatment.
Bicuspid ; Calcium ; Calcium Hydroxide ; Calcium Sulfate ; Dental Cements ; Dental Pulp Cavity ; Dentin ; Hand ; Humans ; Hydrazines ; Hydroxides ; Root Canal Filling Materials ; Tooth ; Vinyl Compounds ; Zinc Oxide

The purpose of this research was to compare the microtensile bond strength of resin coated surface and resin inlay according temporary filling materials prior to applying self-adhesive resin cement. Caviton(GC, Japan), Provifil(Promedica, Neumunster, Germany), Provifil(Promedica, Neumunster, Germany) & petrolatum, and Eugenol-based cement, Tembond(Kerr, Orange CA, USA) were used as temporary filling materials. After fabrication of Tescera(Bisco, Schamburg IL, USA), it was bonded with a self-adhesive resin cement, Rely X unicem(3M, St. Paul. Minn, USA). After this procedure, the microtensile bond strength was measured and it was analyzed through one-way ANOVA and Duncan test(p<0.05). Caviton(GC, Tokyo, Japan) showed statistical difference except for the control(group I) and the saliva(group II)(p<0.05). Provifil(group IV), Provifil & petroneum(group V), Tembond(group VI) had lower microtensile bond strength.
Analysis of Variance ; Calcium Sulfate ; Citrus sinensis ; Dental Cements ; Dentin ; Inlays ; Petrolatum ; Resin Cements ; Root Canal Filling Materials ; Tokyo ; Vinyl Compounds ; Zinc Oxide

Thermogravimetry (TG), TG-MS, Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM)-energy dispersive spectrometer(EDS) were adopted to investigate the pyrolysis characteristics of calamina. According to the findings of the qualitative and quantitative studies on the changes in the content of relevant elements, the whole shape, the functional groups, and the volatile components of calamina before and after being pyrolyzed, the 200-360, 580-750 degrees C were two sensitive temperature ranges related to the changes in effective component during calamina processing. Thermal weight loss was observed for ZnCO3, Zn(OH)2 and ZnCO3-2Zn(OH)2-H2O under 200-360 degrees C and for CaCO3 under 580-750 degrees C. The results of studies on chemical reaction kinetics showed good linear relations. This experiment integrated relevant methods and theories of physical chemistry and science of traditional Chinese medicine processing, and interpretes calamina processing techniques and mechanism, in order to provide a good example for modem studies on other traditional Chinese medicine processing.
Drug Combinations ; Drug Compounding ; methods ; Ferric Compounds ; chemistry ; Kinetics ; Temperature ; Zinc Oxide ; chemistry

OBJECTIVEThe aim of this study is to analyze the processing mechanism of calamine.

METHODXRD, TEM and IR were adopted to analyze the structures and the components of original and calcined calamine. Their antibacterial activities were also determined.

RESULTThe results indicated that zinc carbonate in original calamine was decomposed into zinc oxide after processing at 700 degrees C for 1 hour using original calamine of 40 mesh, and the particle size was smaller than before processing. All of ZnO, ZnCO3 and Zn5 (CO3) 2 (OH) 6 had antibacterial activitives.

CONCLUSIONOriginal calamine is deposed to ZnO after being calcined for 1 h at 700 degrees C and wet milling. The content of ZnO and antibacterial activity of calcined calamine are better than those of original calamine, moreover, the particle size diminishes and become dimensional uniformity, and the contents of dissolved impurities is decreased. The antibacterial activitives of original and calcined calamine are decided by zinc.

Anti-Bacterial Agents ; chemistry ; pharmacology ; Bacteria ; drug effects ; Drug Combinations ; Ferric Compounds ; chemistry ; pharmacology ; Particle Size ; Zinc Oxide ; chemistry ; pharmacology

OBJECTIVETo evaluate the effect of Zinc oxide-eugenol cement and Gluma desensitizer on the sheer bond strength of three kinds of dentin bonding agents. The three dentin bonding agents were Zinc phosphate cement, Glass ionomer cement and Super-Bond C&B. To find the theory depending for the using of different protective methods and the selecting of different kinds of dentin bonding agents in prepared abutment teeth.

METHODSThe buccal surfaces of ninety freshly extracted human premolars were flattened to expose an adequate area of lower dentin. Followed by wet-grinding on a series of silicon carbide paper from number 320, 400, 600 grit to produce the dentin bonding surface. The teeth roots were embedded in self-curing resin with the crown out of the resin. The embedded ninety teeth were divided randomly into three groups. The group A was control and the dentin surfaces were not treated. The group B was covered with a paste of Zinc oxide-eugenol cement. The group C was covered with Gluma desensitizer. Calculating the sheer strength between three bonding agents and dentin after the two treatments of dentin surface. The results were statistically assessed with SPSS software. Dentin surfaces were observed with scanning electron microscope (SEM).

RESULTSThe sheer bond strengths of Zinc phosphate cement had significant decrease (P<0.05), especially the C1 group. The sheer bond strengths of Glass ionomer cement and Super-Bond C&B had no significant difference.

CONCLUSIONZinc oxide-eugenol cement and Gluma desensitizer could reduce the sheer bond strength of Zinc phosphate cement with dentin surface. Zinc oxide-eugenol cement and the Gluma desensitizer could not effect Glass ionomer cement and the Super-Bond C&B with dentin.

Boron Compounds ; Crowns ; Dental Bonding ; Dentin ; Dentin-Bonding Agents ; Glutaral ; Humans ; Methacrylates ; Methylmethacrylates ; Resin Cements ; Zinc Oxide-Eugenol Cement

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

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