RESUMO
A 49-year-old woman presented with unspecific symptoms including polydipsia, increasing fatigue for several weeks, and vague abdominal pain. Serum calcium (5.30 mmol/l; normal range 2.00-2.60) and parathyroid hormone levels (> 2500.0 ng/l; normal range 15.0-68.0) were extremely elevated. Imaging studies showed a huge mediastinal tumor. Based on these findings a hypercalcemic crisis caused by primary hyperparathyroidism was diagnosed. After intensive care treatment and further diagnostic procedures, the patient's parathyroid adenoma was removed by parathyroidectomy. The postoperative course was uneventful.
Assuntos
Dor Abdominal/etiologia , Adenoma/complicações , Adenoma/diagnóstico , Fadiga/etiologia , Neoplasias das Paratireoides/complicações , Neoplasias das Paratireoides/diagnóstico , Polidipsia/etiologia , Dor Abdominal/diagnóstico , Dor Abdominal/prevenção & controle , Adenoma/cirurgia , Diagnóstico Diferencial , Fadiga/diagnóstico , Fadiga/prevenção & controle , Feminino , Humanos , Neoplasias do Mediastino , Pessoa de Meia-Idade , Neoplasias das Paratireoides/cirurgia , Paratireoidectomia , Polidipsia/diagnóstico , Polidipsia/prevenção & controle , Resultado do TratamentoRESUMO
OBJECTIVES: To evaluate changes in the palatal vault after rapid maxillary expansion (RME) with bonded splint appliances. SETTING AND SAMPLE POPULATION: The sample comprised 24 children (12 boys and 12 girls) with mixed dentition (mean age 8.3 years; range 6.4-10.4 years). MATERIALS AND METHODS: Following expansion, the splint appliance was used as a retainer for 6 months and then removed. Study casts were taken before RME (T0) and when the appliance was removed (T1). Then, 3D laser scans were taken to build complete 3D jaw models. Frontal cross sections were constructed at 53-63, 55-65 and 16-26, exported as coordinates, and finite element calculated to quantify their area, width and height. Maxillary length was also determined. RESULTS: Paired t-tests indicated statistically significant increases in the average palatal width (T1-T0=6.53-6.79 mm) and cross-sectional area (T1-T0=20.39-21.39 mm2) after RME (p<0.001). However, small but statistically significant reductions were observed in palatal height (T1-T0=-0.49 mm, only at 55-65; p<0.001) and length (T1-T0=-0.54 mm; p<0.01). Linear regression analysis showed statistically significant (p<0.001) direct correlations between the widths and respective cross-sectional areas. Age did not influence any measurement. The reliability of the measurements was examined with an intraclass correlation coefficient (ICC). We found an ICC>0.99 (p<0.001) for all tested parameters. CONCLUSIONS: Rapid maxillary expansion distinctly increased mean palatal widths and cross-sectional areas. However, palatal height (55-65) and maxillary length decreased to a small extent.
Assuntos
Remodelação Óssea/fisiologia , Maxila/patologia , Técnica de Expansão Palatina , Palato Duro/patologia , Anatomia Transversal , Cefalometria/métodos , Criança , Feminino , Análise de Elementos Finitos , Seguimentos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Lasers , Masculino , Má Oclusão/terapia , Maxila/crescimento & desenvolvimento , Modelos Anatômicos , Desenho de Aparelho Ortodôntico , Contenções Ortodônticas , Técnica de Expansão Palatina/instrumentação , Palato Duro/crescimento & desenvolvimento , Estudos RetrospectivosRESUMO
An average rate of bracket loss of between 4.7 and 6 per cent is to be expected in daily clinical orthodontic practice during a typical 2 year treatment period. For reasons of economy, detached brackets are commonly reattached after sandblasting to remove adhesive, or replaced with used brackets reconditioned by specialist companies. In the present study, sandblasting and specialist bracket-reconditioning procedures were systematically compared by comparative shear testing of rebonded, reconditioned, and new brackets (n = 160) using light- and chemically cured adhesives. Statistical analysis was carried out with Kruskal-Wallis and Mann-Whitney tests. The mean bond strength of reconditioned brackets was, in each case, lower than that of new brackets, with the lowest value obtained with sandblasted brackets. This nevertheless exceeded the minimum recommended value of 5-8 MPa. Bond strength was generally higher with chemically than with light-curing adhesive; the chemically curing adhesive provided bond strength on previously bonded enamel higher than the light-curing adhesive on intact teeth. Consistent with this, the results of the adhesive remnant index (ARI) demonstrated improved bonding with the chemically curing than the light-curing adhesive to the bracket base. Despite resulting in a weaker bond strength compared with new brackets, sandblasting brackets accidentally detached during orthodontic treatment will generally allow effective reattachment to be achieved. Bond strength can be improved with the use of a chemically cured adhesive. Used brackets reconditioned by specialist companies provide a second alternative to new brackets and higher bond strengths than sandblasted brackets.
Assuntos
Colagem Dentária , Reutilização de Equipamento , Braquetes Ortodônticos , Cimentos de Resina , Adesivos/análise , Colagem Dentária/métodos , Análise do Estresse Dentário , Humanos , Microscopia de Força Atômica , Dente Molar , Resistência ao Cisalhamento , Estatísticas não ParamétricasRESUMO
In order to apply high, short-term forces during rapid maxillary expansion (RME) to the sutures of the maxilla with minimum loss of force and without causing unwanted side-effects (dentoalveolar tipping, etc.), the appliance should be as rigid as possible. The retention arms of the RME screws, representing a particularly vulnerable and stressed weak point of RME appliances, were the focus of this laboratory technical study. Retention arms of 16 types of RME screws comprising four arms and one with eight arms were examined using a three-point bending test. According to their ability to absorb the applied bending loads, the screws were classified in product groups from 1 (highest) to 6 (lowest). Fifteen of the tested retention arms (stainless steel), despite having the same diameter (1.48-1.49 mm), differed up to 69.81 per cent between the highest (288.0 N) and lowest (169.6 N) maximum force parameters and up to 66.40 per cent between the highest (3325.9 N/mm(2)) and lowest (1998.7 N/mm(2)) maximum bending stress parameters. Due to optimum formability, though reduced rigidity, a titanium screw for nickel-sensitive patients (group 6) displayed the lowest force and bending tension values. The stainless steel double arms of the eight-arm screw device welded on both ends displayed the highest force data. The mean ductilities of the groups with the most and least rigid single steel arms differed by 22.77 per cent. Statistical analysis using the Pearson correlation coefficient revealed a significant indirect correlation between ductility and both maximum force (r = -0.780, P < 0.001) and maximum bending stress (r = -0.778, P < 0.001). The SUPERscrews, the Tiger Dental four-arm screw (group 1), and the eight-arm screw displayed the highest capacity to absorb an applied bending load. The screws in groups 3-6 appear acceptable for RME during the pre-pubertal period, whereas in the pubertal and post-pubertal period, groups 1 and 2 are sufficient. In early adulthood only the screws in group 1 and especially the eight-arm screw seem advisable, as mechanical demands increase with age.
Assuntos
Análise do Estresse Dentário , Desenho de Aparelho Ortodôntico , Aparelhos Ortodônticos , Técnica de Expansão Palatina/instrumentação , Fatores Etários , Ligas Dentárias , Humanos , Palato Duro/crescimento & desenvolvimento , Projetos Piloto , Maleabilidade , Aço Inoxidável , Estresse MecânicoRESUMO
OBJECTIVES: To assess early versus late treatment of Class III syndrome for skeletal and dental differences. METHODS: Thirty-eight Class III patients treated with a chincup were retrospectively analyzed. Baseline data were obtained by reviewing pretreatment (T0) anamnestic records, cephalograms, and casts. The cases were assigned to an early or a late treatment group based on age at T0 (up to 9 years or older than 9 years but before the pubertal growth spurt). Both groups were further compared based on posttreatment data (T1) and long-term follow-up data collected approximately 25 years after treatment (T2). RESULTS: Early treatment was successful in 74% and late treatment in 67% of cases. More failures were noted among male patients. The late treatment group was characterized post therapeutically by significantly more pronounced skeletal parameters of jaw size relative to normal Class I values; in addition, a greater skeletal discrepancy between maxilla and mandible, higher values for mandibular length, Cond-Pog, ramus height, overjet, anterior posterior dysplasia indicator (APDI), lower anterior face height, and gonial angle were measured at T1. The angle between the AB line and mandibular plane was found to be larger at T0, T1, and T2, as well as more pronounced camouflage positions of the lower anterior teeth at T0. The early treatment group was found to exhibit greater amounts of negative overjet at T0 but more effective correction at T1. CONCLUSIONS: Early treatment of Class III syndrome resulted in greater skeletal changes with less dental compensation.
Assuntos
Aparelhos de Tração Extrabucal/estatística & dados numéricos , Má Oclusão Classe III de Angle/epidemiologia , Má Oclusão Classe III de Angle/terapia , Ortodontia Corretiva/estatística & dados numéricos , Prevenção Secundária/estatística & dados numéricos , Tempo para o Tratamento/estatística & dados numéricos , Áustria/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Estudos Longitudinais , Masculino , Má Oclusão Classe III de Angle/diagnóstico , Ortodontia Corretiva/instrumentação , Prevalência , Estudos Retrospectivos , Distribuição por Sexo , Resultado do TratamentoRESUMO
OBJECTIVES: To investigate the skeletal and dental changes during chincup versus facemask treatment, to compare the long-term effects of the two appliances, and to document the impact of each on treatment success. METHODS: In all, 61 patients with Class III syndrome were retrospectively analyzed at three examination times: 7.8 ± 1.7 years of age (T0, pretreatment), 9.6 ± 2.4 years of age (T1, posttreatment), and around 15-20 years later (T2, long-term follow-up). RESULTS: Significant changes of specific cephalometric parameters for all treatment times: T0-T1 (SNA, interbase and gonial angle, Björk's sum angle, maxillomandibular differential, and distance of upper lip to esthetic line), T1-T2 (NL-NSL, SNB, mandibular-body length, effective mandibular length, and effective maxillary length), and T0-T2 (mandibular-body length, effective mandibular length, effective maxillary length, maxillomandibular differential, SNB, ANB, gonial angle, Björk's sum angle, and Wits appraisal). The T1-T2 results illustrate that in both treatment groups the typical Class III growth pattern often reappeared after treatment, including gains in SNB angle, condylion-gnathion length, and gonion-menton distance. CONCLUSIONS: Either a facemask or a chincup may be effectively used to treat Class III malocclusion. There were differences in long-term stability. Maxillary development was similarly favorable in both groups of patients with successful outcome. The subgroup in whom chincup treatment had failed were mainly characterized by excessive mandibular growth, or lack of maxillary catch-up growth, with deterioration of the maxillomandibular relationship notably in the initial phase of treatment. Early chincup treatment did not have an adverse impact on the temporomandibular joints.
Assuntos
Cefalometria , Aparelhos de Tração Extrabucal , Má Oclusão Classe III de Angle/terapia , Desenho de Aparelho Ortodôntico , Ortodontia Corretiva , Técnicas de Movimentação Dentária , Adolescente , Criança , Feminino , Seguimentos , Humanos , Masculino , Estudos Retrospectivos , Adulto JovemRESUMO
AIM: The present study evaluated the temporal release of Co Cr, Mn, and Ni from the components of a typical orthodontic appliance during simulated orthodontic treatment. MATERIALS AND METHODS: Several commercially available types of bands, brackets, and wires were exposed to an artificial saliva solution for at least 44 days and the metals released were quantified in regular intervals using inductively coupled plasma quadrupole mass spectrometry (ICP-MS, Elan DRC+, Perkin Elmer, USA). Corrosion products encountered on some products were investigated by a scanning electron microscope equipped with an energy dispersive X-ray microanalyzer (EDX). RESULTS: Bands released the largest quantities of Co, Cr, Mn, and Ni, followed by brackets and wires. Three different temporal metal release profiles were observed: (1) constant, though not necessarily linear release, (2) saturation (metal release stopped after a certain time), and (3) an intermediate release profile that showed signs of saturation without reaching saturation. These temporal metal liberation profiles were found to be strongly dependent on the individual test pieces. The corrosion products which developed on some of the bands after a 6-month immersion in artificial saliva and the different metal release profiles of the investigated bands were traced back to different attachments welded onto the bands. CONCLUSION: The use of constant release rates will clearly underestimate metal intake by the patient during the first couple of days and overestimate exposure during the remainder of the treatment which is usually several months long. While our data are consistent with heavy metal release by orthodontic materials at levels well below typical dietary intake, we nevertheless recommend the use of titanium brackets and replacement of the band with a tube in cases of severe Ni or Cr allergy.
Assuntos
Metais , Aparelhos Ortodônticos Removíveis , Braquetes Ortodônticos , Fios Ortodônticos , Corrosão , Humanos , Técnicas In Vitro , Saliva , Saliva Artificial/farmacologiaRESUMO
BACKGROUND: An induction of gastro-oesophageal reflux has been reported after ingestion of alcoholic beverages in healthy volunteers. However, it is unknown whether reflux in gastro-oesophageal reflux disease patients will be enhanced by the ingestion of alcoholic beverages. AIM: To investigate the effects of wine and beer on postprandial reflux in reflux patients. METHODS: Twenty-five patients (reflux oesophagitis 15, non-erosive reflux disease 10; 18 men and seven women) drank 300-mL white wine (n = 17), 500-mL beer (n = 8), or identical amounts of tap water (controls) together with a standardized meal in a randomized order. pH-measurement was carried out during three postprandial hours by pH-metry and the percentage of time pH < 4 was calculated. RESULTS: Both alcoholic beverages increased reflux compared with water [wine 23% (median), water 12%, P < 0.01; beer 25%, water 11%, P < 0.05]. Between wine and beer, no difference in reflux induction was obtained. The reflux induction was seen in patients with (23%, P < 0.01) and without reflux oesophagitis (22%, P < 0.05) and in both sexes (women 23%, men 25%, P < 0.05 each). CONCLUSIONS: Ingestion of commonly consumed alcoholic beverages such as wine and beer induces gastro-oesophageal reflux in gastro-oesophageal reflux disease patients. Therefore, these patients should be advised to avoid the intake of large amounts (> or = 300 mL) of these beverages.
Assuntos
Cerveja/efeitos adversos , Refluxo Gastroesofágico/etiologia , Vinho/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Prandial/fisiologiaRESUMO
BACKGROUND: Patients with reflux disease often complain of heartburn after ingestion of coffee. Induction of gastro-oesophageal reflux has been demonstrated by pH-metry following the intake of coffee in healthy volunteers. The reflux was reduced when the coffee had undergone a decaffeination process. The aim of this study was to investigate the effect of decaffeination of coffee on reflux in patients with reflux disease. METHODS: Seventeen reflux patients underwent two osesophageal 3-h pH measurements. The patients received, in a double-blind study design in a randomized order, 300 mL of either regular or decaffeinated coffee together with a standardized breakfast. The fraction time oesophageal pH < 4 was calculated during the three postprandial hours. RESULTS: For regular coffee the fraction time was calculated to a median of 17.9% with a range of 0.7-56.6%. The fraction time was significantly reduced to 3.1% (0-49.9%) after ingestion of decaffeinated coffee. CONCLUSION: The amount of gastro-oesophageal reflux induced by the intake of regular coffee in patients with reflux disease can be reduce by the decaffeination of coffee.
Assuntos
Cafeína/efeitos adversos , Café/efeitos adversos , Refluxo Gastroesofágico/induzido quimicamente , Idoso , Café/química , Método Duplo-Cego , Feminino , Humanos , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Anticholinergic drugs are known to impair the motor function of the oesophagus but their effects on the oesophageal afferent pathways are unknown. AIM: To determine the effects of a peripherally-acting (trospium chloride) and a centrally-acting (biperiden) anticholinergic drug on the motility and the evoked potentials of the oesophagus. METHODS: Nine healthy volunteers were randomized to receive 1.2 mg trospium chloride (TC), 5 mg biperiden (BIP) or saline i.v. Primary peristalsis was elicited by swallowing a 5 mL water bolus and secondary peristalsis by insufflation of 20 mL air, 10 times each. Oesophageal potentials were evoked by electrical stimulation in the distal and proximal oesophagus (30 stimulations at 0.4 Hz, two runs). RESULTS: Both anticholinergic drugs reduced by a similiar amount the contraction amplitudes (TC 17 mmHg, BIP 25 mmHg, saline 67 mmHg; P < 0.01) and the rate of secondary contractions (TC 60%, BIP 70%, saline 95%; P < 0.01). In contrast, only biperiden prolonged the latencies of the evoked potentials (N1 peak, distal oesophagus: BIP 191 ms, TC 102 ms, saline 101 ms; P < 0.01; P1 peak: BIP 322 ms, TC 161 ms, saline 144 ms; P < 0.01). CONCLUSIONS: Both anticholinergic drugs depress oesophageal motility, but only the centrally-acting anticholinergic drug biperiden modifies the oesophageal evoked potentials, suggesting a central cholinergic transmission of the oesophageal afferent pathways.
Assuntos
Antagonistas Colinérgicos/farmacologia , Esôfago/efeitos dos fármacos , Potenciais Evocados/efeitos dos fármacos , Contração Muscular/efeitos dos fármacos , Adulto , Benzilatos , Biperideno/farmacologia , Método Duplo-Cego , Feminino , Humanos , Masculino , Músculo Liso/efeitos dos fármacos , NortropanosRESUMO
BACKGROUND: Coffee and tea are believed to cause gastro-oesophageal reflux; however, the effects of these beverages and of their major component, caffeine, have not been quantified. The aim of this study was to evaluate gastro-oesophageal reflux induced by coffee and tea before and after a decaffeination process, and to compare it with water and water-containing caffeine. METHODS: Three-hour ambulatory pH-metry was performed on 16 healthy volunteers, who received 300 ml of (i) regular coffee, decaffeinated coffee or tap water (n = 16), (ii) normal tea, decaffeinated tea, tap water, or coffee adapted to normal tea in caffeine concentration (n = 6), and (iii) caffeine-free and caffeine-containing water (n = 8) together with a standardized breakfast. RESULTS: Regular coffee induced a significant (P < 0.05) gastro-oesophageal reflux compared with tap water and normal tea, which were not different from each other. Decaffeination of coffee significantly (P < 0.05) diminished gastro-oesophageal reflux, whereas decaffeination of tea or addition of caffeine to water had no effect. Coffee adapted to normal tea in caffeine concentration significantly (P < 0.05) increased gastro-oesophageal reflux. CONCLUSIONS: Coffee, in contrast to tea, increases gastro-oesophageal reflux, an effect that is less pronounced after decaffeination. Caffeine does not seem to be responsible for gastro-oesophageal reflux which must be attributed to other components of coffee.
Assuntos
Cafeína , Café , Refluxo Gastroesofágico/etiologia , Chá , Adulto , Feminino , Humanos , Masculino , Distribuição Aleatória , ÁguaRESUMO
BACKGROUND: Patients with gastro-oesophageal reflux disease are advised to avoid the ingestion of large meals. In healthy volunteers, a relationship between the amount of postprandial gastro-oesophageal reflux and the volume of a liquid meal has been demonstrated. AIM: To evaluate whether the amount of postprandial gastro-oesophageal reflux is also related to the calorie content of a meal, a second parameter that will be reduced by avoidance of the ingestion of large meals. METHODS: Twelve healthy volunteers (six female, 19-31 years) received two solid-liquid meals with either 842 kcal (solid 582 kcal, liquid 260 kcal) or 582 kcal (31% reduction) in a randomized order. The nutritional components (10% fat, 76% carbohydrates, 14% protein) and the volume of the meals were identical in both meals. The lower oesophageal sphincter pressure was measured continuously in the first postprandial hour with a Dent sleeve, and pH-metry was performed for 3 h postprandially with a glass electrode in the distal oesophagus. Blinded to the type of ingested meal, we calculated the mean lower oesophageal sphincter pressure, the frequency of transient lower oesophageal sphincter relaxations, the number of reflux episodes, and the fraction of time for which pH < 4. RESULTS: A similar decrease in lower oesophageal sphincter pressure was observed after ingestion of the high calorie meal (median 10.9 mmHg, range 4.8-16.7 mmHg) and low calorie meal (median 9.9 mmHg, range 3.9-18.4 mmHg). No difference in the number of transient lower oesophageal sphincter relaxations (high calorie: median 9 per hour, range 5-13 per hour; low calorie: median 7 per hour, range 0-14 per hour) and of reflux episodes (high calorie: median 12 in 3 h, range 3-22 in 3 h; low calorie: median 12 in 3 h, range 3-30 in 3 h) was registered after intake of both types of meal. Additionally, no difference was identified regarding the fraction of time for which pH < 4 between the high calorie (mean 2.3%, 0.2-23.7%) and low calorie meal (3.3%, 0.5-17.8%). CONCLUSION: Reducing the caloric density of a meal neither influences postprandial lower oesophageal sphincter pressure nor decreases gastro-oesophageal reflux in healthy volunteers. Thus, the amount of gastro-oesophageal reflux induced by ingestion of a meal seems to depend on the volume but not on the caloric density of a meal.
Assuntos
Dieta , Ingestão de Energia/fisiologia , Junção Esofagogástrica/fisiopatologia , Alimentos , Refluxo Gastroesofágico/fisiopatologia , Motilidade Gastrointestinal , Adulto , Feminino , Humanos , Masculino , Período Pós-PrandialRESUMO
BACKGROUND AND OBJECTIVES: Controversial data are reported on the diagnostic yield of oesophageal pH-monitoring in clinical routine. The aim of this study was to determine the diagnostic importance of oesophageal pH-monitoring in the work-up of functional thoraco-abdominal disorders. METHODS: The prevalence of abnormalities in pH-monitoring was evaluated in 238 patients with functional complaints: typical reflux symptoms (n = 56), non-cardiac chest pain (n = 98), non-ulcer dyspepsia (n = 52), and unclassifiable abdominal pain (n = 32). A symptom index was calculated for reflux-related symptoms in patients experiencing symptoms during the measurement (n = 74). RESULTS: The rate of patients with an abnormal pH-monitoring were in patients with reflux symptoms non-cardiac chest pain, non-ulcer dyspepsia and unclassified abdominal pain 55, 50, 44 and 34%, respectively. A symptom index of at least 50% was observed in 77, 55, 50 and 60% in the four groups respectively. CONCLUSION: The high rate of abnormal oesophageal pH-monitoring and symptom related reflux events in the investigated patients emphasizes the importance of 24-hour oesophageal pH-measurement in the diagnostic work-up of functional thoracic and abdominal disorders.
Assuntos
Dor Abdominal/etiologia , Refluxo Gastroesofágico/fisiopatologia , Concentração de Íons de Hidrogênio , Doenças Torácicas/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Refluxo Gastroesofágico/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
Pathological gastroesophageal reflux, prolonged gastric emptying and abnormal gastric potential difference have been claimed to be functional disorders often detectable in non-ulcer dyspspsia (NUD). The role of Helicobacter pylori in NUD is still unclear. The aim of the present study was to evaluate the prevalence of these factors in 47 patients with NUD. According to DeMeester's criteria, 60 percent of NUD patients had abnormal gastroesophageal reflux, while 38 percent had prolonged gastric emptying of a liquid meal. Seventy-nine percent showed abnormal gastric potential difference which was unrelated to Helicobacter pylori colonization, detected in 46 percent of NUD patients. When esophageal pHmetry, gastric emptying evaluation and measurement of gastric potential difference were performed, 89 percent of NUD patients presented at least one abnormal finding.
Assuntos
Dispepsia/fisiopatologia , Esôfago/fisiopatologia , Esvaziamento Gástrico/fisiologia , Antro Pilórico/fisiologia , Adulto , Idoso , Dispepsia/etiologia , Dispepsia/microbiologia , Feminino , Refluxo Gastroesofágico/complicações , Refluxo Gastroesofágico/fisiopatologia , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/fisiopatologia , Helicobacter pylori/isolamento & purificação , Humanos , Concentração de Íons de Hidrogênio , Masculino , Potenciais da Membrana/fisiologia , Pessoa de Meia-Idade , Valores de ReferênciaAssuntos
Eritromicina/uso terapêutico , Esvaziamento Gástrico/efeitos dos fármacos , Refluxo Gastroesofágico/tratamento farmacológico , Adulto , Eritromicina/farmacologia , Feminino , Refluxo Gastroesofágico/induzido quimicamente , Refluxo Gastroesofágico/fisiopatologia , Humanos , Concentração de Íons de Hidrogênio , Masculino , Valores de Referência , Vinho/efeitos adversosRESUMO
Self-etching primers have simplified the process of direct bonding of dental resins, by eliminating the rinsing step after etching in conventional bonding, for example. Although it is generally assumed that all of the applied self-etching primer is incorporated into the resin, the possibility that a substantial amount remains free and extractable into a person's saliva has not been investigated. The aim of the present study was to examine this issue by bonding brackets to extracted teeth with self-etching primers under controlled conditions and determining the proportion of the applied phosphoric acid ester that is subsequently extractable by high-performance liquid chromatography. Approximately half of the applied acid ester was extractable and thus not integrated into the polymeric network following standard light curing. This was reduced to 40% when the curing time was doubled. Acid ester leaching was a rapid process that was essentially completed within an hour.
Assuntos
Adesivos Dentinários/química , Organofosfatos/química , Condicionamento Ácido do Dente/métodos , Cromatografia Líquida de Alta Pressão , Lâmpadas de Polimerização Dentária , Colagem Dentária , Humanos , Espectroscopia de Ressonância Magnética , Teste de Materiais , Braquetes Ortodônticos , Polímeros/química , Cimentos de Resina/química , Cloreto de Sódio , Fatores de TempoRESUMO
The aim of this in vitro study was to investigate both shear bond strength (SBS) by shear testing of indirectly bonded brackets, and the accuracy of a new transfer method, the Aptus bonding device (ABD). For comparison, the SBS of directly bonded brackets in two experimental arrangements was also measured. The precision of the positioning of the indirect bracket transfer was assessed by photographic superimposition and three-dimensional (3D) measurement of the bracket positions on the working and plaster models using a 3D laser scan. Statistical analysis was carried out by means of descriptive and explorative data using the SPSS program. To compare groups, a one-factor analysis of variance and post hoc tests (Tukey-HSD) were used. The level of significance was set at P < 0.05. SBS using indirect and direct bonding, with the same experimental arrangement and the same adhesives (Concise and Transbond), showed no significant differences. For direct bonding, using only one adhesive (Transbond), lower values were observed, but they were only statistically significant for the premolar teeth. The clinically required minimum bond strength of 6 MPa was achieved in all groups. Superimposition of the photographs of the indirectly bonded upper labial segment brackets showed no deviations. The results of the 3D measurement of the positions of the brackets on the working and plaster models only yielded small deviations (0.15 mm along the X-axis in the centre, 0.17 mm along the Y-axis, and 0.19 mm along the Z-axis). The ABD is a useful adjunct to bond placement and does not compromise bond strength.
Assuntos
Colagem Dentária/métodos , Braquetes Ortodônticos , Bis-Fenol A-Glicidil Metacrilato/química , Colagem Dentária/instrumentação , Cimentos Dentários/química , Humanos , Imageamento Tridimensional , Lasers , Teste de Materiais , Modelos Dentários , Fotografação , Cimentos de Resina/química , Resistência ao Cisalhamento , Estresse MecânicoRESUMO
The aim of this study was to compare, by shear testing, the bond strengths after 1 and 24 hours of a light-cured resin (Enlight) and a light-cured glass ionomer cement GIC (Fuji Ortho LC) using various polymerization lamps (halogen, high performance halogen, xenon, and diode) for the direct bonding of brackets. The self-curing resin (Concise) was used as the control. The analysis was carried out using the SPSS program. For group comparison purposes, the single factor variance analysis (ANOVA) and the post-hoc test (Tukey's HSD) were used. The level of significance was established at P < 0.05. When comparing two mean values the t-test for independent random samples was employed. All polymerization lamps achieved the minimum bond strength of 5-8 MPa. With Enlight LV, bond strength was dependent on curing time (the halogen lamp achieved the highest bond strength of 10.0 MPa, P < 0.001, with a curing time of 40 seconds. The other lamps showed similar results) and on the mode of cure (the highest bond strength values were achieved by four-sided curing, P= 0.04). Fuji Ortho LC, on the other hand, was independent of the duration of light curing and the type of lamp used. The bond strengths of the resin-modified glass ionomer cement (RMGIC) were similar to or somewhat higher than those achieved with light-cured composite resin (P = 0.039) when lamps with short polymerization times were used, but were significantly lower (P< 0.001) when compared with the self-curing composite adhesive. After 24 hours, the bond strengths of all adhesives showed a significant increase: Enlight 19 per cent, Fuji Ortho LC 6.6 per cent, Concise 16 per cent. Bond failure occurred for Enlight at the bracket-composite resin adhesive interface in 90 per cent and with Concise in 57 per cent. However, Fuji Ortho LC showed far more cohesive and mixed failures, indicating an improved bond between bracket and cement.
Assuntos
Adesivos , Colagem Dentária/métodos , Braquetes Ortodônticos , Resistência ao Cisalhamento , Análise de Variância , Bis-Fenol A-Glicidil Metacrilato , Humanos , Teste de Materiais/métodosRESUMO
The aim of this study was to compare polymerization lamps of various technologies (halogen, high performance halogen, xenon, i.e. plasma arc, as well as diode lamps) to determine the degree of polymerization of composite probes using Fourier-transform infrared (FTIR) spectroscopy. To observe the light-induced curing reaction under a bracket, an attenuated total reflection (ATR)-FTIR was used. The results showed that the recommended curing times for all the polymerization lamps tested were adequate for successful polymerization of the composite used (degree of conversion approximately 60 per cent, which did not exceed 66 per cent after longer curing times). However, even after very long curing times, delayed curing of the composite must be taken into consideration as there was a decrease of approximately 10 per cent in FTIR band intensities (1637 and 3104 cm(-1)). ATR-FTIR spectroscopy showed that when bonding brackets with materials cured by light, uncured areas remain in the centre of the lowest layer of the adhesive.
Assuntos
Resinas Acrílicas , Resinas Compostas , Colagem Dentária , Iluminação/instrumentação , Poliuretanos , Espectroscopia de Infravermelho com Transformada de Fourier , Humanos , Fatores de TempoRESUMO
BACKGROUND: White wine and beer induce gastroesophageal reflux (GER). We investigated the effects of white and red wine on lower esophageal sphincter pressure (LESP) and GER. METHODS: Twenty healthy volunteers received 300 ml white wine, red wine, or water together with a standardized meal. The LESP was continuously monitored with a Dent sleeve the 1st h postprandially, and the esophageal pH measured with a glass pH electrode. RESULTS: The LESP was decreased after intake of white wine (median, 14.9 mmHg; range, 5.6-19.5 mmHg) compared with red wine (20.4 mmHg; 13.1-22.3 mmHg; P < 0.05) and tap water (19.5 mmHg; 16.2-29.1 mmHg; P < 0.01). The fraction time esophageal pH <4 was increased after both alcoholic beverages compared with tap water (0.9%; 0.2-5.8%; P < 0.01 versus white wine, P < 0.05 versus red wine) with a greater fraction time after white wine (13.2; 0.3-58.1 ) than after red wine (2.3; 0.7-24.4; P < 0.05). The decreased sphincter pressure after white wine was accompanied by a change in the reflux pattern with increased 'stress reflux' and the occurrence of 'free reflux'. CONCLUSION: White wine and red wine exert different effects on LESP and GER.