Effect of length post and remaining root tissue on fracture resistance of fibre posts relined with resin composite.

To investigate the influence of post length and amount of remaining root tissue on the fracture resistance of roots restored with fibre posts relined with resin composite. Ninety upper canine teeth were divided into nine groups (n = 10). The post spaces were prepared resulting in different lengths, as follows: group 2/3, preparations with lengths of 10 mm; group 1/2, preparations with lengths of 7·5 mm; and group 1/3, preparations with lengths of 5 mm. Each group was divided into 3 subgroups according to amount of remaining root tooth tissue (2, 1 mm or 0·5 mm of thick root). Fibre posts relined with resin composite were cemented, and all teeth were restored with metal crowns. The samples were submitted to the fracture resistance test in a universal testing machine, at an angle of 135° and speed of 0·5 mm min(-1) . Failure modes were observed and the data of fracture resistance were submitted to the anova and Tukey's (α = 0·05). No statistically significant difference in fracture resistance was found among different post lengths (P > 0·05). Remaining dentin thickness of 2 and 1 mm did not differ statistically in fracture resistance (P > 0·05), which was higher than of 0·5 mm dentin thickness (P < 0·05). A prevalence of repairable failure was observed in all groups. It can be concluded that the length of fibre post relined with resin composite did not influence fracture resistance, but thickness was an important factor for the restoration of endodontically treated teeth.

Effect of root canal sealers on bond strength of fibreglass posts cemented with self-adhesive resin cements.

AIM: This study evaluated the effects of different root canal sealers on the bond strength of a fibreglass post cemented with self-adhesive resin cements. METHODOLOGY: The root canals of 50 extracted maxillary single-rooted canine teeth were prepared with the crown-down technique and randomly divided into five groups according to the sealer used: group 1: control group, gutta-percha points only (no sealer); group 2: AH Plus (resin-based sealer); group 3: self-etch Epiphany (resin-based sealer); group 4: Sealer 26 (calcium hydroxide-based sealer); and group 5: Endomethasone (zinc oxide eugenol-based sealer). The root canals were filled with gutta-percha, the cold lateral compaction technique, except for group 3 where Resilon was used. Post spaces were prepared, and fibreglass posts were cemented with the self-adhesive cement RelyX Unicem. Bonded specimens were sectioned into 1-mm-thick slabs, and a push-out test was performed in a universal machine. Failure modes were observed and classified into five types: (i) adhesive between the post and resin cement; (ii) mixed, with resin cement covering 0-50% of the post diameter; (iii) mixed, with resin cement covering 50-100% of the post surface; (iv) adhesive between resin cement and root canal; and (v) cohesive in dentine. Data of bond strength were submitted to anova and Tukey test (α = 0.05). RESULTS: No significant difference was detected between control group, AH Plus, Epiphany and Sealer 26 (P > 0.05). The Endomethasone group had significantly lower bond strength values than the other sealers (P < 0.05). The prevalence of mixed fractures and adhesive cement-dentine failure was verified in the eugenol-containing sealer group; in the control group, the resin-based and calcium hydroxide-based sealer groups, the predominant mode of failure was the mixed type. CONCLUSION: Endomethasone interfered negatively with the bond to root dentine; however, AH Plus, Epiphany and Sealer 26 did not interfere in the bond strength of a fibreglass post cemented with self-adhesive resin cements.

Evaluation of the dentogingival area during early plaque formation.

BACKGROUND: The aims of this investigation were to evaluate the pattern of supragingival plaque formation in the dentogingival area within 96 hours after abstinence from mechanical plaque control and to clinically analyze the gingival inflammatory response observed. METHODS: Six male volunteers, 20 to 23 years of age, had their upper incisors and cuspids polished. Four independent periods of no mechanical plaque control--24, 48, 72, and 96 hours--were instituted. In each period, plaque was disclosed and standardized individual photographs were taken. Impressions were taken and replicas were analyzed by scanning electron microscopy. Gingival crevicular fluid (GCF) was collected at baseline and 96 hours. The height of the gingival papilla was measured at baseline, 24, and 96 hours. RESULTS: Results showed the presence of a plaque-free zone (PFZ) along the gingival margin up to 72 hours. After 96 hours, there was a significant reduction in the presence of PFZ in the proximal thirds of the buccal surface when compared to the other experimental periods. At the end of the study, there was a significant increase in the GCF flow as well as edema of the interdental papilla, when compared to baseline values. CONCLUSIONS: The PFZ observed during the initial phase was less apparent at the 96-hour period. At this time, there was an increase in the gingival inflammatory response, represented clinically by increased GCF flow and edema.

Antihypertensive, vasodilator and antioxidant effects of a vinifera grape skin extract.

Cumulative evidence suggests that moderate wine consumption exerts a cardioprotective effect. We investigated the occurrence of an antihypertensive effect of an alcohol-free hydroalcoholic grape skin extract (GSE) obtained from skins of a vinifera grape (Vitis labrusca) in experimental rodent hypertension models. The vasodilator effect of GSE (polyphenols concentration 55.5 mg g(-1)) was also assessed in the isolated mesenteric vascular bed of Wistar rats and the antioxidant effect was studied on lipid peroxidation of hepatic microsomes. Oral administration of GSE significantly reduced systolic, mean and diastolic arterial pressure in Wistar rats with desoxycorticosterone acetate-salt and N(G)-nitro-L-arginine methyl ester (L-NAME) induced experimental hypertension. In the rat isolated mesenteric vascular bed pre-contracted with norepinephrine, bolus injections of GSE induced endothelium-dependent vasodilatation that was substantially inhibited by L-NAME, but not by indometacin, tetraethylammonium or glibenclamide. Lipid peroxidation of hepatic microsomes estimated as malondialdehyde production was concentration-dependently inhibited by GSE. In conclusion, the antihypertensive effect of GSE might be owing to a combination of vasodilator and antioxidant actions of GSE. These findings also suggest that the beneficial effect of moderate red wine consumption could be owing to an antihypertensive action induced by compounds occurring in the skin of vinifera grapes.

Diagnosis of approximal caries in primary teeth: radiographic versus clinical examination using tooth separation.

PURPOSE: To compare the accuracy of clinical examination performed with bitewing radiographs or clinical examination using tooth separation to identify carious lesion activity. MATERIALS AND METHODS: 320 surfaces from 40 bitewing radiographs were examined for approximal caries on the maxillary and mandibular primary molars of 20 patients 3-10 years old. The patients were divided into three groups: (1) Absence of the permanent first molar; (2) Partial eruption of the permanent first molar; and (3) Full eruption of the permanent first molar. Two examiners evaluated the radiographs using a megascope, a magnifying glass (x2), and an amplifying image screen. Approximal radiolucencies were identified on 72 surfaces. Following the radiographic examinations, the two examiners performed conventional clinical inspection using a No. 4 dental mirror, a No. 5 dental explorer, and an air-water syringe, with artificial light and relative isolation. The separation method was performed with elastic bands, which were removed after 24 hours, and the clinical examination conducted as in the non-separation group. RESULTS: The correlation between the extension of interproximal radiolucent lesions in primary dentition and their clinical diagnoses following separation of the teeth, was similar to findings on literature evaluating the permanent dentition. On radiographic findings for enamel lesions, white spots predominated both in the inner (100%) and in the outer (94%) half of enamel upon clinical examination with separation of teeth. For radiolucent lesions in dentin, on the other hand, cavities predominated over white spot lesions (84%). In Groups 1 and 2 (young primary), white spots occurred in cases where the radiolucent lesions reached the dentin (15% and 25%), similar to findings for young permanent teeth. Clinical diagnosis performed with the mechanical separation of teeth cannot be considered conclusive for the primary dentition.

Invasive technique of pit and fissure sealants in primary molars: a SEM study.

One of the alternatives used when the clinical inspection of the fissure is doubtful is the invasive technique. This study used the SEM, to investigate two kinds of burs in doing the invasive technique upon primary molars, as well as to test the suitability of two kinds of sealants (with and without filler particles) to penetrate into such preparations. The points hereby tested revealed to be adequate in obtaining a minimal opening in the enamel, allowing the inspection of the fissure, and at the expense of a slight removal of dubious tissue, permitting a preparation of easy clinical performance. In regard to sealant penetration, no difference was seen between the self-cured sealant and the light-cured sealant.

Ethylenediaminetetraacetic acid and citric acid solutions for smear layer removal in primary tooth root canals.

PURPOSE: The purpose of this in vitro study was to evaluate, via scanning electron microscopy, the micromorphology of the dentine walls of primary anterior teeth with focus on the presence of the smear layer after endodontic debridement and final irrigation with different systems. METHODS: Thirty primary maxillary anterior teeth were assigned to 3 groups according to the final irrigant solution. Group 1 received 1% sodium hypochlorite; Group 2 received 17% EDTA followed by 1% sodium hypochlorite; and Group 3 received 6% citric acid followed by 1% sodium hypochlorite. The canals were debrided using 1% sodium hypochlorite to a size 30 file, and the final irrigation was performed with one of the 3 irrigants as assigned. The teeth were prepared for examination of the canal walls by electron microscopy for the presence or absence of the smear layer. RESULTS: Group 1 had significantly higher scores for remaining smear layer than Groups 2 and 3 (P<.01), while Groups 2 and 3 presented similar smear layer score values. CONCLUSIONS: Sodium hypochlorite promoted the formation of a smear layer during shaping, and the use of EDTA and citric acid facilitated smear layer removal.

Case report: Clinical, histological and ultrastructural characterization of type II dentinogenesis imperfecta.

BACKGROUND: Type II dentinogenesis imperfecta (DGIII) is an autosomal dominant dental development anomaly that affects both the primary and permanent dentition. CASE REPORT: This case report describes the clinical, radiographic and morphological characteristics of the teeth of a seven-year-old child with DGI-II determined by optical microscopy and scanning electron microscopy. TREATMENT: This consisted of extraction of the primary teeth with periapical lesions due to the advanced state of tooth resorption. Aesthetic restorations were performed on the mandibular anterior teeth and occlusal fissure sealants were applied to erupting teeth. A removable partial upper denture was made in order to return anterior aesthetic function and to aid mastication and speech. FOLLOW UP: The child was examined at 3 month intervals. Over the following 3 years the prosthesis was replaced due to facial growth and fluoride was applied at each follow-up visit to all teeth. The patient remains in follow up and management. CONCLUSION: Individuals with DGI-II must not neglect their dental health. Early diagnosis, professional advice and treatment with periodic follow-up can help improve the quality of life of such patients.

Utilização experimental de hidroxiapatita sintética em alvéolos dentários de gatos domésticos (Felis catus): estudo clínico, radiográfico e histomorfométrico / Experimental application of hydroxyapatite in feline (Felis catus) dental sockets: clinic, radiographic, histologic and histomorphometric studies

A fim de avaliar a resposta biológica da hidroxiapatita sintética (HAP-91) nos alvéolos de felinos domésticos, este biomaterial foi implantado após extração do terceiro pré-molar inferior direito em 12 gatos e mantida por meio de uma membrana de celulose bacteriana. No lado esquerdo, os alvéolos foram apenas recobertos com a membrana de celulose bacteriana, formando o grupo-controle. Observou-se, durante a avaliação clínica, que todos os animais voltaram a comer normalmente ração úmida, sem apresentarem sinais de dor ou desconforto após a recuperação anestésica. A cicatrização da ferida cirúrgica ocorreu de forma satisfatória, sendo que a membrana de celulose bacteriana evitou a saída precoce da hidroxiapatita. Radiograficamente, aos 50 dias, todos os animais apresentaram radiopacidade óssea homogênea em ambos os lados. À análise histomorfométrica, observou-se adiantamento do processo de reparo do osso alveolar nos oito primeiros dias do grupo-tratado quando comparado ao grupo-controle, bem como atraso aos 30 dias, porém, aos 50 dias, ambos os grupos apresentavam porcentagem de tecido ósseo semelhante e morfologicamente normal. Os resultados sugerem que a hidroxiapatita é biocompatível, integra-se ao tecido ósseo alveolar e pode ser utilizada em felinos.

The biocompatibility of a material depends on its characteristics, as well as the species and the environment recipient. In order to evaluate the biological response of the synthetic hydroxyapatite (HAP-91) in feline dental alveoli, it was implanted in the right inferior third premolar after extraction in 12 cats and maintained through a bacterial cellulose membrane. On the left side the alveoli was covered with a bacterial cellulose membrane (control group). During clinical evaluations it was observed that the animals started to eat after the anesthetic recovery time, without clinical signs of pain. There was a satisfactory cicatrization of the surgical wound and the bacterial cellulose membrane aided in repairing the gum, avoiding the loss of the hydroxyapatite. Radiographs taken 50 days post surgery presented homogeneous bone radiopacity on both sides. The histological and histomorfometrical analysis showed a positive progress of the alveolar repair in the first 8 days in the treated group when compared to the control group and a delay at 30 days, however at 50 days both presented a similar and morphologically normal percentage of bone tissue. These findings suggest that HAP-91 is biocompatible and integrates into the feline alveolar bone.

Cricopharyngeal dysfunction in a patient with achalasia.

A 64-year-old man had intense dysphagia and aspiration of 1 month's duration. The patient had lower esophageal sphincter (LES) achalasia and cricopharyngeal dysfunction, with generalized muscle weakness discovered by neurologic examination. Endoscopy showed no lesions of the mouth, pharynx, larynx, or esophagus. The diagnosis of achalasia was made by manometry. The LES did not relax with deglutition; the contractions in the esophageal body were nonperistaltic and of low amplitude; and the upper esophageal sphincter pressure did not decrease after deglutition. A scintigraphic study of the oral and pharyngeal phases of swallowing showed a mouth and pharyngeal retention of 90% of the volume swallowed.

Renal dysplasia in a Boxer dog: case report / Displasia renal em um cão Boxer: relato de caso

A 20-month-old female Boxer dog presented significant increase on the bilateral volume of the maxillaries. The necropsy revealed that the kidneys were reduced in size, pale, with lobular aspect, and reduced cortical-medullar ratio. The maxillaries cutting surface revealed trabecular aspect of brown-reddish color. In addition, the lesions observed by microscopy (asynchronic differentiation of nephrons, persistent mesenchyme, and atypical tubular epithelium) allowed establishing the diagnosis of renal dysplasia with secondary fibrous osteodystrophy.

Uma cadela Boxer com 20 meses de idade apresentou grande aumento de volume bilateral nos maxilares. À necropsia, os rins apresentavam-se diminuídos de tamanho, pálidos, com aspecto lobular e relação córtico-medular reduzida. A superfície de corte dos maxilares revelou aspecto trabecular de coloração marrom-avermelhada. As lesões observadas à microscopia (diferenciação assincrônica de néfrons, mesênquima persistente e proliferação tubular atípica) permitiram estabelecer o diagnóstico de displasia renal com osteodistrofia fibrosa secundária.