Although formaldehyde is well known to cause type 4 hypersensitivity, immunoglobulin E (IgE)-mediated hypersensitivity to formaldehyde is rare. Here, we report a case of recurrent generalized urticaria after endodontic treatment using a para-formaldehyde (PFA)-containing root canal sealant and present a review of previous studies describing cases of immediate hypersensitivity reactions to formaldehyde. A 50-year-old man visited our allergy clinic for recurrent generalized urticaria several hours after endodontic treatment. Prick tests to latex, lidocaine, and formaldehyde showed negative reactions. However, swelling and redness at the prick site continued for several days. The level of formaldehyde-specific IgE was high (class 4). Thus, the patient was deemed to have experienced an IgE-mediated hypersensitivity reaction caused by the PFA used in the root canal disinfectant. Accordingly, we suggest that physicians should pay attention to type I hypersensitivity reactions to root canal disinfectants, even if the symptoms occur several hours after exposure.
Disinfectants/*adverse effects ; Formaldehyde/*adverse effects ; Humans ; Hypersensitivity, Immediate/*chemically induced ; Immunoglobulin E/*immunology ; Male ; Middle Aged ; Recurrence ; Skin Tests ; Time Factors ; Urticaria/*chemically induced/diagnosis ; Zinc Oxide-Eugenol Cement/*chemistry

The time domain entombment of bacteria by intratubular mineralization following orthograde canal obturation with mineral trioxide aggregate (MTA) was studied by scanning electron microscopy (SEM). Single-rooted human premolars (n=60) were instrumented to an apical size #50/0.06 using ProFile and treated as follows: Group 1 (n=10) was filled with phosphate buffered saline (PBS); Group 2 (n=10) was incubated with Enterococcus faecalis for 3 weeks, and then filled with PBS; Group 3 (n=20) was obturated orthograde with a paste of OrthoMTA (BioMTA, Seoul, Korea) and PBS; and Group 4 (n=20) was incubated with E. faecalis for 3 weeks and then obturated with OrthoMTA-PBS paste. Following their treatments, the coronal openings were sealed with PBS-soaked cotton and intermediate restorative material (IRM), and the roots were then stored in PBS for 1, 2, 4, 8 or 16 weeks. After each incubation period, the roots were split and their dentin/MTA interfaces examined in both longitudinal and horizontal directions by SEM. There appeared to be an increase in intratubular mineralization over time in the OrthoMTA-filled roots (Groups 3 and 4). Furthermore, there was a gradual entombment of bacteria within the dentinal tubules in the E. faecalis inoculated MTA-filled roots (Group 4). Therefore, the orthograde obturation of root canals with OrthoMTA mixed with PBS may create a favorable environment for bacterial entombment by intratubular mineralization.
Aluminum Compounds ; therapeutic use ; Calcification, Physiologic ; physiology ; Calcium Compounds ; therapeutic use ; Crystallization ; Dental Pulp Cavity ; microbiology ; Dentin ; microbiology ; Drug Combinations ; Enterococcus faecalis ; ultrastructure ; Humans ; Methylmethacrylates ; therapeutic use ; Microscopy, Electron, Scanning ; Oxides ; therapeutic use ; Root Canal Filling Materials ; therapeutic use ; Root Canal Obturation ; methods ; Root Canal Preparation ; instrumentation ; Silicates ; therapeutic use ; Time Factors ; Zinc Oxide-Eugenol Cement ; therapeutic use

OBJECTIVETo observe the influence of different bonding process and three different root canal sealing materials on microstructure of root canal dentin bonding interface after fiber post and resin bonding, so as to improve clinical operation steps and to optimize fiber post resin bonding effect.

METHODSFifteen human single mandibular first premolars were selected. Three were bonded with fiber posts through Relyx Unicem conventional bonding steps after filled with root canal sealing materials of zinc oxide eugenol paste (Group A), and another three were bonded through the same steps after filled with sealing materials of Vitapex (Group B). The other nine were filled with sealing materials of AH Plus, randomly divided into three groups and bonded through different steps as follows: conventional bonding steps only (Group C), etching with 35% phosphoric acid before conventional bonding steps (Group D), and etching and coating with Singlebond 2 adhesive before conventional bonding steps (Group E). After immersed in saline solution for one week, all the roots were cut into three sections of 3 mm in thickness with emery chip and numbered as crown section, middle section and tip section respectively. The samples were observed the resin protrusion in mixed layer of dentin interface and dentinal tubules by scanning electron microscopy.

RESULTSWe observed the resin protrusion in microstructures of the roots bonded through Relyx Unicem after filled with three different root canal sealing materials (Group A, B, C, E): most obvious in the root crown sections, middle in the root middle sections and least in the root tip sections. Differences were observed in roots filled with different sealing materials: little resin protrusion were observed in crown sections only in Group A and B, but large number of resin protrusion were found in crown and middle sections in Group C-E. Compared with Group C, no more resin protrusion were found in Group D. More and elongated resin protrusions were found in Group E.

CONCLUSIONSWe recommend using AH Plus as root canal sealing materials for residual crown and root needed to strengthen by fiber post. It is no need to etch before Relyx Unicem conventional bonding steps. However, coating Singlebond 2 adhesive after acid etching has the potential to increase fiber post cementation.

Acid Etching, Dental ; methods ; Calcium Hydroxide ; Dental Bonding ; methods ; Dental Pulp Cavity ; ultrastructure ; Dentin ; ultrastructure ; Dentin-Bonding Agents ; chemistry ; Epoxy Resins ; Humans ; Mandible ; ultrastructure ; Microscopy, Electron, Scanning ; Molar ; ultrastructure ; Post and Core Technique ; Resin Cements ; Root Canal Filling Materials ; chemistry ; Silicones ; Tooth Root ; ultrastructure ; Zinc Oxide-Eugenol Cement

OBJECTIVETo introduce a modified model for quantitative testing of glucose microleakage by constant air pressure and evaluate the sealing ability of four root canal sealers including AU Plus, Roeko Seal, Cortisomol and RC Sealer.

METHODSFifty-six straight maxillary anterior teetb were randomly divided into four experimental groups with 12 samples in each group, group A: AH Plus, group B: Roeko Seal, group C: Cortisomol, group D: RC Sealer, and positive and negative control group with 4 samples in each. After regular root preparation, samples in experimental groups were obturated by cold gutta-percha lateral compaction technique with sealers according to group description. Control groups were obturated with cold gutta-percha only. Through the model above, the value of glucose microleakage from crown to root was measured at 1, 3, 5, 7, 10, 15, 20, 25, 30 days with the glucose oxidase-peroxidase method (GOD-POD).

RESULTSAt day 1, 3, 5, no significant difference of microleakage was found between group A and B (P > 0.05). The same result was also seen between group C and D. From 7 days, microleakage value in each experimental group gradually increased, and statistical difference was found between groups (P < 0.05).

CONCLUSIONThis new model using constant air pressure is easy to establish, sensitive and practical. Among all the sealers evaluated, polydimethylsiloxane based root canal sealer, Roeko Seal has the greatest sealing ability, while epoxy-amine resin based AH Plus is second and Zinc Oxide based Cortisomol and RC Sealer have the least sealing ability.

Air Pressure ; Dental Cements ; Dental Leakage ; Dental Pulp Cavity ; Epoxy Resins ; Glucose ; Gutta-Percha ; Humans ; Root Canal Filling Materials ; Zinc Oxide-Eugenol Cement

Eugenol (4-allyl-2-methoxyphenol) is a naturally occurring phenolic compound that is widely used in dentistry as a component of zinc oxide eugenol cement that is commonly applied to the mouth environment. Cisplatin is one of the most potent known anticancer agents and shows significant clinical activity against a variety of solid tumors. This study was undertaken to investigate the synergistic apoptotic effects of co-treatments with eugenol and cisplatin on human melanoma (G361) cells. To investigate whether this co-treatment efficiently reduces the viability of G361 cells compared with each single treatment, an MTT assay was conducted. The induction and augmentation of apoptosis were confirmed by DNA electrophoresis, Hoechst staining and an analysis of DNA hypoploidy. Western blot analysis and immunofluorescent staining were also performed to evaluate the expression levels and the translocation of apoptosis-related proteins following this co-treatment. Furthermore, proteasome activity and mitochondrial membrane potential (MMP) changes were also assayed. The results indicated that a co-treatment with eugenol and cisplatin induced multiple pathways and processes associated with an apoptotic response in G361 cells including nuclear condensation, DNA fragmentation, a reduction in MMP and proteasome activity, the increase and decrease of Bax and Bcl-2, a decreased DNA content, the release of cytochrome c into the cytosol, the translocation of AIF and DFF40 (CAD) into the nucleus, and the activation of caspase-9, caspase-7, caspase-3, PARP and DFF45 (ICAD). In contrast, separate treatments of 300 microM eugenol or 3 microM cisplatin for 24 h did not induce apoptosis. Our present data thus suggest that a combination therapy of eugenol and cisplatin is a potential treatment strategy for human melanoma.
Antineoplastic Agents ; Apoptosis ; Blotting, Western ; Caspase 3 ; Caspase 7 ; Caspase 9 ; Cisplatin ; Cytochromes c ; Cytosol ; Dentistry ; DNA ; DNA Fragmentation ; Electrophoresis ; Eugenol ; Humans ; Melanoma ; Membrane Potential, Mitochondrial ; Mouth ; Phenol ; Proteasome Endopeptidase Complex ; Proteins ; Zinc Oxide-Eugenol Cement

OBJECTIVETo study the effects of two different endodontic sealers on the bond strength of two fiber posts cemented with adhesive resin cement.

METHODSTwenty-eight crownless human maxillary central incisors were prepared with the step-back technique and randomly divided into four groups according endodontic sealer and fiber: Group A, Cortisomol sealer+Matchpost fiber post; Group B, Cortisomol sealer+Macrolock fiber post; Group C, Guttaflow sealer+Matchpost fiber post; Group D, Guttaflow sealer+Macrolock fiber post. One week after fiber posts were bonded, a thin-slice push-out test was performed in a universal machine. Morphologic structure of the root canal dentin surfaces etched and the adhesive interfaces were examined by scanning electron microscopy (SEM).

RESULTSThe bond strengths of 4 groups were (7.06 +/- 3.22), (9.31 +/- 3.61), (6.90 +/- 3.13), (9.71 +/- 3.42) MPa. The bond strengths of group B and D were significantly higher than that of group A and C (P < 0.05). There was no significant difference between group A and C, group B and D (P > 0.05). The cervical third had the highest mean push-out bond strength, next to middle third and apical third (P < 0.01). SEM showed that larger numbers of the dentin tubules were open after the root canals were etched and penetration of resin tags into the dentinal tubules increased in the coronal root region when compared with the apical root region.

CONCLUSIONThe shear bond strength doesn't have relationship with endodontic sealers. The serration significantly increases the retention of fiber post. The bond strengths are different at the three root segment sites.

Dental Bonding ; Dentin ; Dentin-Bonding Agents ; Dimethylpolysiloxanes ; Drug Combinations ; Gutta-Percha ; Humans ; Incisor ; Post and Core Technique ; Resin Cements ; Root Canal Therapy ; Tooth Root ; Zinc Oxide-Eugenol Cement

OBJECTIVETo investigate the influence of sealer placement on apical sealability in root canal treatment.

METHODS100 extracted single root canal teeth were selected. All canals were prepared by manual Protaper instrument in a step-back way. The samples were divided into 5 groups randomly. A group: 30 samples, sealer placement by chief gutta percha; B group: 30 samples, sealer placement by K file; C group: 30 samples, sealer placement by spreader; D group: 5 samples, a positive control; E group: 5 samples, a negative control. There were 2 subsets in each experimental group which were obturated by lateral gutta percha with or without sealer. Glucose oxidase method was used to measure the apical leakage at the 1st 2nd, 4th, 7th, 10th, 15th, 20th, 25th, 30th day of the experiment.

RESULTSApical sealability varied with different sealer placement methods (F=4.832, P=0.001). Sealer placement by chief gutta percha (A group) had the best instant apical sealability. However, lateral gutta percha with or without sealer didn't affect the apical sealibility.

CONCLUSIONPlacing the same kind sealer in different ways can affect the apical sealability. There were no significant differences of the apical leakage no matter the lateral gutta percha with or without sealer. In order to get better instant apical sealability and simplify the clinic operation, placing the sealer with a chief gutta percha while the lateral gutta percha without sealer is recommended.

Dental Leakage ; Dental Pulp Cavity ; Gutta-Percha ; Humans ; Root Canal Obturation ; Root Canal Preparation ; Zinc Oxide-Eugenol Cement

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

OBJECTIVEThe purpose of this study was to compare the quality of apical seal of the canals that obturated with differently tapered gutta-percha cone using continuous wave technique.

METHODS62 extracted human mandible incisors were prepared with Gates-Glidden drill and Hero642 to a final file of No. 30 and 0.06 taper. The teeth were randomly separated into 0.02 taper group (30 teeth), 0.06 taper group (30 teeth) and positive control group (2 teeth). The teeth of 0.02 taper group and 0.06 taper group were respectively obturated with a 0.02, or 0.06 tapered gutta-percha cone and Cortisomol sealer using warm vertical condensation technique separately. The teeth of positive control group were not obturated. In 0.02 taper group and 0.06 taper group, 10 teeth were placed in India ink for 24 hours, 10 teeth were placed in India ink for 10 days, 10 teeth were placed in India ink for 90 hours after 67 days storage in Hank's balanced salt solution. The teeth of positive control group were placed in India ink for 24 hours. The apical leakage was evaluated by the linear measurement under the stereomicroscope.

RESULTSThe dye penetration of positive control group was along the whole canals. The apical leakage of 0.02 taper group increased along with time, while no difference was found among 0.06 taper group. There was a significant difference in the degree of leakage between 0.02 taper group and 0.06 taper group in 67 days (P = 0.041), but not in 24 hours and 10 days groups (P = 0.601, P = 0.471).

CONCLUSIONBetter apical seal was obtained when using the same tapered gutta-percha cone with root canal.

Dental Leakage ; Gutta-Percha ; Humans ; Incisor ; Molar ; Root Canal Obturation ; Zinc Oxide-Eugenol Cement

OBJECTIVETo compare the apical microleakage of Vitapex (calcium hydroxide based paste) with that of AH-plus and zinc oxide eugenol sealer when used with laterally condensed gutta percha obturation technique.

METHODSOne hundred single rooted human anterior teeth were instrumented and randomly divided into three experimental groups (A, B, C) of 30 teeth each and two control groups (D, E) of 5 teeth each. Group A was filled with laterally condensed gutta-percha using Vitapex as sealer. Group B was filled with laterally condensed gutta-percha using AH-plus as sealer. Group C was filled with laterally condensed gutta-percha using zinc oxide eugenol as sealer. Group D was the positive control. Group E was the negative control, which were coated with nail polish to entire root surface. Teeth were then suspended in 2% methylene blue. After this, teeth were demineralized dehydrated and cleared. Linear dye penetration was determined under stereomicroscope with calibrated eye piece.

RESULTSThe mean dye penetration for group A, B, C were respectively (0.57 +/- 0.56) mm, (0.79 +/- 0.96) mm and (1.07 +/- 1.12) mm. Group D demonstrated maximum dye penetration. Group E showed no dye penetration. There was no statistically significant difference between group B and group C (P > 0.05). However, there was statistically significant difference between group A and group B, C (P < 0.01).

CONCLUSIONThis study showed that Vitapex used as endodontic sealer material are better than AH-plus sealer and zinc oxide eugenol sealer.

Calcium Hydroxide ; Dental Leakage ; Dental Pulp Cavity ; Gutta-Percha ; Humans ; Molar ; Root Canal Filling Materials ; Root Canal Obturation ; Silicones ; Zinc Oxide-Eugenol Cement