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Objective: This study evaluated through stereomicroscopy the effectiveness of hand and rotary instrumentation techniques, either isolated or combined, in the preparation of oval-shaped root canals. Materials and method: Thirty single-rooted human mandibular incisors were selected. After endodontic access and coronal preflaring, teeth were mounted in a modified Bramante muffle and then sectioned transversely at 3 and 6 mm from the root apex. Images of each section were made under a stereomicroscope at 30× magnification. Teeth were reassembled in the muffle and divided into three groups (n=10) according to the root canal preparation technique: GI - rotary preparation with Mtwo™ basic sequence (10/.04; 15/.05; 20/.06; 25/.06), followed by Mtwo™ complementary instruments (30/.05; 35/.04; 40/.04); GII - rotary preparation with Mtwo™ basic sequence, complemented by hand instruments (#30, #35 and #40); GIII - hand instrumentation using the conventional technique (#10 to #40). All instruments were used in brushing motion. The muffles were separated again so that new images of each section could be obtained. The following parameters were evaluated in pre- and postoperative images: root canal area; perimeter; mesiodistal (MD) and buccolingual (BL) diameters; and mesial (M) and distal (D) wall thickness. Next, the values measured in post- and preoperative images were subtracted for comparison of experimental groups. Data were analyzed using the Kruskal-Wallis test (α=0.05). Results: No significant difference between groups was observed for all parameters. Conclusion: There was no difference among hand, rotary, or combined instrumentation; all techniques were able to increase root canal area, perimeter, and diameter in MD and BL directions. Moreover, the amount of dentin wear on proximal root canal walls was similar for all tested groups. Keywords: Endodontics. Microscopy. Root canal preparation. Root canal therapy. Stereomicroscopy.
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AIM: To analyse the root canal morphology of mandibular third molars using clearing technique. MATERIAL AND METHODS: Ninety permanent extracted mandibular third molar teeth were collected based on inclusion and exclusion criteria. Teeth were then decalcified and were made transparent Methylene Blue Dye was injected to color the pulp space. These teeth were then observed under sterio Microscope and root canal systems were identified according to Vertucci's Classification. RESULTS: The most common anatomical morphology found was having two roots. Overall type I Vertucci's configuration was the most common pattern of canals. Other canal patterns that were found included type II, III, IV and V. In this study no canal of type VI, VII or VIII were found. CONCLUSION: The morphological variations in root patterns and canal configuration of mandibular third molar should be given consideration for successful endodontic treatment.
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Aims: The present study was conducted to confirm the angiogenic potential of honey using Chick Chorioallantoic Membrane (CAM), an in ovo model and to study its effect on Vascular Endothelial Growth Factor (VEGF) expression in the CAM tissue. Attempts were also made to identify the probable active constituents present in honey that contributed to its angiogenic potential. Methodology: Honey was evaluated over concentrations ranging from 0.015 to 25% v/v and the extent of angiogenesis was quantified using stereomicroscopy. VEGF expression at transcript level was determined by RT-PCR. Erythropoietin and Heparin were used as positive and negative controls respectively. Four known constituents of honey viz., Glucose, Proline, Vitamin C and Hydrogen peroxide were tested by biochemical methods. Results: New blood formation was seen at all the concentrations tested, however the proangiogenic effect was greater at lower concentrations. These results were significantly greater than that seen with erythropoietin, the positive control. VEGF mRNA expression in CAM tissue also demonstrated similar findings. Among the constituents tested, Vitamin C and Hydrogen peroxide were observed to be associated with the angiogenic effect of honey. Conclusion: The study thus confirms the pro-angiogenic potential of honey at low concentrations. This effect is probably due to the presence of Hydrogen peroxide and Vitamin C and is mediated via alteration in VEGF expression.
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PURPOSE: This study assessed the effect of preparation design on marginal adaptation and also compared the sensitivity and specificity of clinical evaluation techniques for marginal accuracy of cast restorations to stereomicroscopy. MATERIALS AND METHODS: Three Ivorine molar teeth of different designs were prepared. (A)-A complete crown preparation with buccal shoulder and beveled finish line. (B)-A complete crown preparation with chamfer finish line. (C)-A three-quarter crown preparation with proximal boxes and beveled finish line. Twenty four castings were prepared with eight castings for each design respectively. Each casting underwent examination with an explorer, disclosing media, and a stereomicroscope. Stereomicroscopy at a value less than or equal to 30 microns was used as a gold standard to evaluate the significance of different designs on marginal adaptation. Chi-square tests of independence and Kruskal-Wallis were used to evaluate the effect of preparation design and compare the agreement between examination methods for detection of marginal gap size of greater than or equal to 30 microns (alpha=.05). Sensitivity and specificity for explorer and disclosing media as compared to stereomicroscope was calculated using statistical formula given by Park. RESULTS: The preparation design did not significantly affect overall marginal adaptation. Examination by explorer and disclosing media at 30 microm revealed 39% and 10.06% sensitivity and 91% and 82% specificity respectively. CONCLUSION: Preparation designs examined in this study did not significantly affect the marginal adaptation of the castings. Commonly used clinical evaluation techniques using explorer and disclosing media appeared to be inadequate for assessment of marginal accuracy.
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Crowns , Molar , Sensitivity and Specificity , Shoulder , ToothABSTRACT
Objetivo: O objetivo deste estudo foi analisar as características de cárie secundária e sua relação com a presença de restaurações com defeitos marginais como gap, degrau negativa (NL, a falta de material restaurador) e degrau positiva (PL, saliência). Materiais e Métodos: Oitenta superfícies proximais de restaurações de resina classe II foram fotografados e analisados utilizando um microscópio estereoscópico (X40). Foi registrada a presença de cáries secundárias externas, gaps, NL, PL e após a remoção de restaurações, a presença de lesão interna. Todos os exames foram realizados em 10 pontos bem definidos. Resultados: A prevalência de cárie secundária e gap foram associados com margem gengival. As restaurações com defeitos marginais (NL e PL) não foram associados a qualquer local específico (vestibular, lingual ou gengival). Observou-se uma relação entre esses defeitos com a prevalência de cárie secundária. A presença da lesão interna foi associada com lesão externa. Embora, em 141 pontos foi observada lesão interna, sem a presença de lesão externa. A maioria destas lesões mostraram envolvimento de esmalte interno. Apenas 8 por cento tinham desmineralização restrito a dentina, que poderia sugerir cárie residuais.
Objective: The aim of this study was to analyze the features of secondary caries and their relationship with the presence of restorations marginal defects as gap, negative ledge (NL, lack of restorative material) and positive ledge (PL, overhang). Materials and methods: Eighty proximal surfaces of Class II resin restorations were photographed and analyzed using a stereomicroscope (X40). It was recorded the presence of external secondary caries, gaps, NL, PL and after the restorations removal, the presence of internal lesion. All the exams were done in 10 welldefined points. Results: The prevalence of secondary caries and gap were associated with gingival margin. The restorations marginal defects (NL and PL) were not associated with any specific location (buccal, lingual or gingival). It was observed a relationship between these defects with secondary caries prevalence (gap: p= 0.004; NL and PL: p= 0.017). This association could be explained by the biofilm accumulation usually observed in the interface tooth surface/ restoration marginal defects. The presence of internal lesion was associated with external lesion. Although, in 141 points was observed internal lesion without the presence of external lesion. The majority of these lesions showed internal enamel involvement. Only 8 percent had demineralization restricted to dentine, which could suggest residual caries. Conclusion: The results of this study showed that secondary caries lesion frequently began externally on the interface tooth/restoration, where diagnose, control and arrestment of the lesions is possible.
Subject(s)
Composite Resins , Dental Caries , Microscopy , Dental Restoration, Permanent/adverse effects , Surface PropertiesABSTRACT
Objective To investigate the relationship between early colonic cancer and the pit patterns of abnormal colonic mucosa. Methods We examined the pit patterns of 124 polypi in 139 patients by magnifying colonoscopy and stereomicroscopy, and compared the relations between the pit patterns and pathological diagnosis of polypi. Results 5 cases of LST(laterally spreading tumor)and 9 cases of advanced cancer were found out of 124 polypi in 139 patients. 1 among these 5 cases of LST showed Ⅲ L pit pattern, and 4 showed Ⅳ pit pattern with both magnifying colonoscopy and stereomicroscopy. Magnifying colonoscopy showed high coincidence rate with stereomicroscopy. Conclusion Pit patterns are found to be very important in disguishing tumorous lesions from non-tumorous lesions, and to discover early colonic cancer. Ⅴ pit pattern indicates that the polyp is carcinomatous.
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BACKGROUND AND AIMS: To investigate the morphological and histopathological associations between an individual pit seen on stereomicroscopy or magnifying colonoscopy and an individual crypt seen in histological sections of colorectal tumors. METHODS: Fifty two colorectal lesions were examined by colonoscopy. The mucosal pits of the lesions were observed using a magnifying colonoscopy with a zoom 1 to 100 magnification after administering indigo carmine spray. The pits of the excised specimens were observed by using a stereomicroscopy after 0.2% cresyl violet stain. The pit patterns were classified into six types: normal round pit (I); asteroid pit (II); small round pit (IIIs); large tubular pit (IIIL); gyrus-like pit (IV); and non-structural pattern or amorphysm (V). Histologic diagnoses were determined by H&E staining under light microscopy. RESULTS: The histologic findings according to the pit patterns were 1 chronic nonspecific inflammation and 1 submucosal tumor in 2 cases with type I pit pattern; 4 hyperplastic polyps in 4 cases with type II; 1 hyperplastic polyp, 16 adenomas with low-grade dysplasia, 3 adenomas with high-grade dysplasia, and 1 carcinoma in situ in 21 cases with type IIIL; 4 adenomas with low-grade dysplasia, 3 adenomas with high-grade dysplasia, and 4 carcinoma in situ in 11 cases with type IV; 1 adenoma with low-grade dysplasia in 1 case with type II IIIL; 3 adenomas with low-grade dysplasia, 4 adenomas with high-grade dysplasia, and 2 carcinoma in situ in 9 cases with type IIIL IV; 1 adenoma with high-grade dysplasia, 2 carcinoma in situ, and 1 adenocarcinoma in 4 cases with type IV V. In assessing the histologic findings according to pit pattern by stereomicroscopy, the overall diagnostic predictive value was 82.6% (43/52), and the diagnostic accuracy in differential diagnosis between nonneoplastic and neoplastic lesions was 98% (51/52). The ratio of agreement of the pit pattern between the magnifying colonoscopy and the stereomicroscopy was 68% (17/25). CONCLUSIONS: The results suggest that there was a close correlation between the pit patterns and the histologic findings of colorectal tumors, and that the observation of pit patterns of colorectal lesions provides a differential diagnosis between neoplastic and nonneoplastic lesions.