Influence of the spatulation of two zinc oxide-eugenol-based sealers on the obturation of lateral canals.
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The objective of this research was to evaluate, in vitro, the importance of the correct manipulation of endodontic sealers, correlating it with flow rate and with the consequent obturation of root canals. Twenty-four human canines were prepared, 1 mm from the apex, with K-files up to size 50, by means of the step-back technique. Six lateral canals were then drilled in each tooth, with size 10 file fixed to a low-speed handpiece. The teeth were randomly divided into 4 groups, and root canals were obturated either with the Endomethasoneregister mark or target sealer or Grossman sealer, prepared at ideal or incorrect clinical consistency. After obturation by means of the lateral condensation technique, the teeth were radiographed and evaluated as to the number of sealed lateral canals. Statistical analysis revealed significant differences (p < 0.001) between the tested sealers, and indicated the higher capacity of the well-manipulated Grossman sealer to fill lateral canals. It can be concluded that the flow rate of a sealer and its correct manipulation are very important for the satisfactory obturation of lateral canals. (+info)
Adverse reactions associated with the use of eugenol in dentistry.
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Eugenol is a material commonly used in dentistry with few reported side effects. It is not however, a bio-friendly material when in contact with oral soft tissues. It can produce both local irritative and cytotoxic effects, as well as hypersensitivity reactions. Here we report on two cases of adverse local reaction to eugenol, contained within a temporary restorative material and a temporary cementation material respectively, which illustrate these problems. (+info)
Tissue reactions after intraosseous implantation of three retrofilling materials.
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Bone tissue reactions to EBA, IRM, and cyanoacrylate cement (Base Liner) were studied in the rat mandible using an intraosseous implant method. Osseous cavities (1.4 mm in diameter) were surgically created in the mandibles, and materials were implanted in 60 male Wistar rats. Each specimen was evaluated histologically after 4 and 8 weeks. The development of fibrous connective tissue in direct apposition to the material was observed in the EBA and IRM groups at 4 weeks. A slight degree of macrophage infiltration was seen in the EBA group. After the 8-week observation period, IRM and EBA were frequently separated from the bone cavity by a fibrous connective tissue layer (p < 0.01). The Base Liner appeared to be in direct apposition to the osseous tissue in several areas (p < 0.01). These findings indicate that Base Liner reacts favorably with osseous tissue, compared with the EBA and IRM materials tested and seems to be a biocompatible material. (+info)
A new procedure of the tensile fatigue test for dental materials.
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A new tensile fatigue test using a stainless steel screw was introduced. A transparent PMMA rod was selected as the test material. A hole was drilled and tapped into the rod; a screw was put into the rod with dental cement or without cementation. Three types of cyclic loads were applied to the test piece; the number of times the load was applied when the initial crack was observed and when the final fracture occurred were recorded. Surface observation showed that actual fatigue fractures occurred in the test piece. The preferred applied load waveform was the cyclic haver-triangles load because of the small coefficient of variance. Fatigue strengths of test pieces with and without cementation were different. Cementation improved the fatigue properties, and the type of cement had an effect on the fatigue properties. Although the number of final fractures minus the number of initial cracks was the constant regardless of the type of cement used. (+info)
Histopathological reactions of calcium phosphate cement.
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Calcium phosphate cement (CPC) consisting of Ca4 (PO4)2O and CaHPO4 (2H2O) was recently developed. This study evaluated in vivo aspects of CPC and CPC mixtures compared to those of commercial hydroxyapatite (HP) and several endodontic materials: Grossman's cement (GC), calcium hydroxide-iodine paste (CHP) and gutta-percha plate (GP). Biocompatibility of subcutaneous implants in Donryu rats was evaluated after one month. Results showed very slight inflammatory reactions from CPC, CPC mixtures and HP. The materials were surrounded by thin fibrous connective tissues with a small number of lymphocytes and plasma cells. Severe inflammatory reactions were provoked by GC. Granulation tissues induced by CHP resembled those of pseudoxanthomatous granuloma. The GP material was encapsulated by relatively thick fibrous connective tissues with little inflammatory reactions. (+info)
Outcomes of vital primary incisor ferric sulfate pulpotomy and root canal therapy.
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PURPOSE: To compare ferric sulfate (FS) pulpotomy and primary tooth root canal therapy (RCT) in cariously exposed vital pulps of primary incisors. METHODS: A total of 133 incisors in 50 children were randomly selected to be treated by FS pulpotomy (64) or RCT (69). RESULTS: Two years after treatment, 77 incisors (41 FS pulpotomy, 36 RCT) were available for clinical and radiographic examination. There was no clinical evidence of pathosis in 78% of FS pulpotomy-treated and 100% of RCT-treated incisors. Two independent pediatric dentists evaluated periapical radiographs of the treated incisors. Incisors were classified into 1 of 4 treatment outcomes: N, normal treated incisor; H, nonpathologic radiographic change present; PO, pathologic change present, but not requiring immediate extraction; PX, pathologic change present, extract immediately. Survival analysis was applied. A moderate level of agreement between raters was found for incisors with outcome PX (K = 0.54). Intra-rater reliability was substantial for incisors with outcome PX (K = 0.61). No difference was demonstrated in the proportion of FS pulpotomy- and RCT-treated incisors rated PX at the 2-year recall (x2 = 0.6). RCT incisors demonstrated a significantly higher survival rate than FS pulpotomy incisors at 2 years (p = 0.04). CONCLUSIONS: Treatment outcomes for RCT incisors were not significantly different from FS pulpotomy-treated incisors at 2 years; however, at 2 years the survival rate of RCT incisors was statistically greater than that of FS pulpotomy-treated incisors. (+info)
Effect of eugenol and non-eugenol containing temporary cement on permanent cement retention and microhardness of cured composite resin.
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This present study had three aims: 1) to evaluate the bond strengths of carboxylate and resin cements in cementing cast Co-Cr crowns to pretreatment of composite resin cores with eugenol and non-eugenol containing temporary cements, 2) to determine the microhardness of composite resin treated with temporary cement, 3) to view the surface differences of composite resin with SEM. The composite cores were divided into three experimental groups for the following pretreatments: Group 1, No treatment was provided, Group 2, The external walls of the composite cores were covered with eugenol-containing temporary cement, Group 3, The external walls of the composite cores were covered with non-eugenol containing temporary cement. Analysis of variance results showed that there was a significant difference between all three groups. Temporary cement with eugenol was significantly reduced the bond strength of full crown casting with resin cement compared with non-eugenol. The resin specimens treated with the eugenol-containing temporary cement showed the lowest microhardness values, the non-eugenol-containing temporary cement was not significantly different from those of the control groups. (+info)
Effects of oral environment stabilization procedures on counts of Candida spp. in children.
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The effects of oral environment stabilization procedures on counts of Candida spp. have rarely been discussed, and no conclusive results are found in the literature. The aim of this study was thus to ascertain the effects of oral environment stabilization procedures with glass ionomer and zinc oxide-eugenol cements on counts of Candida spp. in the oral cavity of children. For this purpose, oral rinses of sterile phosphate-buffered saline were initially collected from 30 boys and 30 girls, positive for Candida in the saliva and aged from 4 to 10 years. Data on the initial quantity of CFU/ml of Candida were obtained. Then, the children were randomly divided into two groups and oral environment stabilization procedures were performed using zinc oxide-eugenol cement or glass ionomer cement. One week after the procedures were performed, oral rinses were collected again and final Candida counts were obtained. An expressive reduction in Candida counts was observed in both groups. The zinc oxide-eugenol and glass ionomer cements were efficient in the reduction of Candida counts and statistically significant differences were observed between initial and final counts in both groups. Considering the percentage of reduction, the zinc oxide-eugenol cement presented more favorable results, with a reduction of 70%. A reduction of 46% was observed with the use of the glass ionomer cement. According to the obtained results, we concluded that oral environment stabilization procedures were efficient in reducing Candida spp. counts, especially when the zinc oxide-eugenol cement was employed. (+info)