21st-century endodontics.
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BACKGROUND: Endodontics as a discipline has offered patients the opportunity to maintain their natural teeth. As the population expands and ages, the demand for endodontic therapy can be expected to increase as patients seek dental options to keep their teeth for a lifetime. CLINICAL IMPLICATIONS: New materials, techniques and instruments are entering the market-place to assist dentists in providing patients with more predictable and reliable endodontic treatment. In addition, these new systems make the delivery of endodontic services more efficient. This article describes these advances in endodontic treatment for dentists interested in incorporating these advances into their clinical practice. (+info)
Periapical surgery of 29 teeth. A comparison of conventional technique, microsaw and ultrasound.
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OBJECTIVES: A clinical and radiological study is made of the results obtained with different periapical surgical techniques. MATERIAL AND METHODS: Twenty-nine single-root teeth from 29 patients with periapical pathology following correct endodontic treatment were divided into three groups: (A) 10 patients in which rotary instruments were used to perform osteotomy, apicoectomy and cavity preparation; (B) 10 patients in which rotary instruments were used to perform osteotomy and apical resection, with ultrasound root-end cavity preparation; and (C) 9 patients in which microsaws were used for osteotomy, and ultrasound for cavity preparation. All teeth were filled with IRM. Clinical and radiological controls were made after 10 days, one and 6 months, and one year. RESULTS: Clinical success with the absence of symptoms was achieved in 17 cases (58.6%), while in 16 patients (55.2%) the X-ray images showed complete bony regeneration (complete healing). The clinical success rate after one year was 40%, 70% and 66.7% in groups A, B and C, respectively, while complete radiographic healing was recorded in 30%, 60% and 77.8%. There were three failures in group A, two in group C, and none in group B. CONCLUSION: In conclusion, the best results were obtained when ultrasound was used for root-end cavity preparation. (+info)
A study of cavity preparation by Er:YAG laser--observation of hard tooth structures by laser scanning microscope and examination of the time necessary to remove caries.
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The purpose of this study was to observe and measure the morphological changes that occur in the hard tissue after the application of Er:YAG laser. Another objective was to evaluate and compare the duration of application of both the laser apparatus and a conventional cutting device. In this study, sound and newly extracted carious tissues were used. The morphological changes in hard tooth structures produced by Er:YAG laser irradiation were examined by using a laser scanning microscope. Results showed that appropriate laser irradiation was 100 mJ/pulse for dentin, and 200 mJ/pulse for enamel. Also, the laser scanning microscope images were less damaged than the SEM images due to pretreatment of the specimens. The time taken to remove carious enamel by laser irradiation was slightly longer than the compared rotary cutting device; however, no differences between the two methods were observed in case of carious dentin removal. (+info)
Quantitative analysis of dental porcelain surfaces following different treatments: correlation between parameters obtained by a surface profiling instrument.
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This investigation compared, by quantitative analysis, the surface roughness of dental porcelain submitted to three different treatments (glaze, trimming and polishing), utilizing a surface profiling instrument. The parameters Ra (median roughness), Rz (median of the maximum profile heights of five sample lengths), Rpm (median of the maximum profile heights related to the median line of five sample lengths), Pc (peak count per centimeter) and Rpm/Rz (proportional parameter) were evaluated. In addition, the correlation between Ra and the other parameters was analyzed. Based on the results obtained, it was seen that the Ra parameter did not present any correlation with the other parameters in some of the situations evaluated. This demonstrates that complementation of the measurement with other parameters is always necessary, providing a better evaluation of the functional properties of a surface. (+info)
A study of cavity preparation by Er:YAG laser. Effects on the marginal leakage of composite resin restoration.
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The purpose of this study was to evaluate marginal leakage of composite resin restoration from cavities prepared by Er:YAG laser. The observation of the dentin surface after the application of laser irradiation was performed by LSM, the cutting surface showed a rough surface similar to scales, and exposed dentinal tubules were observed without striations or a smeared layer formation that were observed when using a rotary cutting device. Leakage tests revealed no significant differences in the marginal seal for both enamel and dentin between cavities prepared by Er:YAG laser irradiation and when using an air-turbine. In this study, the usefulness of cavity preparation by Er:YAG laser irradiation in composite resin restoration was suggested. (+info)
Microbial contamination in dental unit waterlines.
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The quality of water in a dental unit is of considerable importance because patients and dental staff are regularly exposed to water and aerosol generated from the dental unit. The aim of this study was to evaluate the occurrence of microbial contamination in dental unit waterlines. Water samples were collected aseptically from the waterlines (reservoir, triple-syringe, high-speed) of 15 dental units. After serial dilution to 1:10(6) in APHA, the samples were seeded by the pour-plate technique and cultured in plate count agar (Difco) for 48 h at 32 degrees C. Analysis was based on the number of colony forming units (CFU). The Wilcoxon non-parametric test indicated that the levels of water contamination were highest in the triple-syringe (13 of 15) and in the high-speed (11 of 15); both levels were higher than those of the water reservoir. There was no significant statistical difference between the level of contamination in the triple-syringe and the high-speed as determined by the Mann-Whitney test [p(H0) = 40.98%; Z = - 0.2281]. Because biofilm forms on solid surfaces constantly bathed by liquid where microorganisms are present, these results indicate that the water in the dental unit may be contaminated by biofilm that forms in these tubules. (+info)
Grindability of dental cast Ti-Ag and Ti-Cu alloys.
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Experimental Ti-Ag alloys (5, 10, and 20 mass% Ag) and Ti-Cu alloys (2, 5, and 10 mass% Cu) were cast into magnesia molds using a dental casting machine, and their grindability was investigated. At the lowest grinding speed (500 m min(-1)), there were no statistical differences among the grindability values of the titanium and titanium alloys. The grindability of the alloys increased as the grinding speed increased. At the highest grinding speed (1500 m x min(-1)), the grindability of the 20% Ag, 5% Cu, and 10% Cu alloys was significantly higher than that of titanium. It was found that alloying with silver or copper improved the grindability of titanium, particularly at a high speed. It appeared that the decrease in elongation caused by the precipitation of small amounts of intermetallic compounds primarily contributed to the favorable grindability of the experimental alloys. (+info)
Comparison of the effects of various periodontal rotary instruments on surface characteristics of root surface.
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The efficacy of scaling and root planing using various periodontal rotary instruments was examined. Eighty extracted human teeth with a history of periodontal disease were divided into four groups of 20 and subjected to one of the following procedures: Use of 1) a Root Burnisher, 2) a Perio Planing Bur (both rotating instruments for contra angle handpieces), 3) a Tooth Planing Bur (rotating instrument for use with an air turbine), or 4) a Gracey Scaler. In each case, the time required for cleaning was measured. Twenty healthy extracted human teeth were used as untreated controls. After treatment, the surface roughness of 10 specimens out of each group were measured using a profilometer and observed by scanning electron microscopy (SEM). Half of the samples were then incubated in dishes with a suspension of fibroblasts. After counting the number of attached cells, the attachment of fibroblasts was observed by SEM. The root surfaces treated with the rotary instruments appeared smooth and there were no significant differences between groups. From the SEM observations, smooth root surfaces with different surface textures were evident and a tight attachment of fibroblasts was observed. The results of this study suggest that use of rotary instruments is superior for periodontal scaling and root planing. (+info)