Effect of surface treatments on the bond strength of different resin teeth to complete denture base material.

Although different commercial brands of artificial teeth are available in the market, debonding from the denture base is still an issue when rehabilitating edentulous patients with conventional or implant-supported complete dentures. The purpose of this study was to investigate the effect of surface treatments on the bond strength of four artificial teeth brands to a denture base material polymerized by microwave energy. Forty anterior artificial teeth of each brand (Biolux, Trilux, Biotone IPN, and Vipi Dent Plus) were bonded to denture base material (VipiWave). Before processing, groups often specimens of each brand received surface treatment: control, monomer application (MA), air abrasion (AA) or diatoric cavity (DC). After processing, a blinded examiner conducted the bond test by applying load to the specimens (0.5 mm/min, to 45 degrees). Data were analyzed by one-way ANOVA followed by Tukey's test (alpha = 0.05). Biolux teeth have stronger bonding to denture base than Trilux (p < 0.05) in control group; higher bond values than Biotone IPN (p < 0.05) in MA group; and higher bond strength than Vipi Dent Plus and Trilux (p < 0.01) in DC group; AA had no differential effect for any of the brands. With regard to the effect of the surface treatments on bond strength within groups of commercial brand, statistical analysis revealed no difference among them. According to results in general, Biolux teeth had the strongest bonding to the denture base material polymerized by microwave energy. Results may assist dentists in selecting denture teeth from the standpoint of shear bond strength.

Effect of surface treatments on the bond strength of different resin teeth to complete denture base material. / Effect of surface treatments on the bond strength of different resin teeth to complete denture base material.

Although different commercial brands of artificial teeth are available in the market, debonding from the denture base is still an issue when rehabilitating edentulous patients with conventional or implant-supported complete dentures. The purpose of this study was to investigate the effect of surface treatments on the bond strength of four artificial teeth brands to a denture base material polymerized by microwave energy. Forty anterior artificial teeth of each brand (Biolux, Trilux, Biotone IPN, and Vipi Dent Plus) were bonded to denture base material (VipiWave). Before processing, groups often specimens of each brand received surface treatment: control, monomer application (MA), air abrasion (AA) or diatoric cavity (DC). After processing, a blinded examiner conducted the bond test by applying load to the specimens (0.5 mm/min, to 45 degrees). Data were analyzed by one-way ANOVA followed by Tukeys test (alpha = 0.05). Biolux teeth have stronger bonding to denture base than Trilux (p < 0.05) in control group; higher bond values than Biotone IPN (p < 0.05) in MA group; and higher bond strength than Vipi Dent Plus and Trilux (p < 0.01) in DC group; AA had no differential effect for any of the brands. With regard to the effect of the surface treatments on bond strength within groups of commercial brand, statistical analysis revealed no difference among them. According to results in general, Biolux teeth had the strongest bonding to the denture base material polymerized by microwave energy. Results may assist dentists in selecting denture teeth from the standpoint of shear bond strength.

Pre-operative evaluation of cervical adenopathies in tumours of the upper aerodigestive tract.

BACKGROUND: Carcinomas of the upper aerodigestive tract are characterized by a high incidence of local metastasis in the neck. The presence of lymph node metastasis represents the most unfavorable prognostic factor for these tumors. A diagnostic routine is needed in order to identify the highest number of neck metastasis, thereby optimizing the selection of patients eligible for surgical neck treatment and reduce costs and length of hospital stay. MATERIALS AND METHODS: Our study analyzes the sensibility, specificity, and diagnostic accuracy of clinical examination, echography (US), computed tomography (CT) in cervical metastasis detection by comparing them with the histopathological examination of the neck dissection specimens (pN) in 53 patients suffering from carcinoma of the upper aerodigestive tract. RESULTS: Clinical examination: sensibility 82.1%; specificity 80%; diagnostic accuracy 81.1%; US with a cut off point for minimal adenopathy diameter of 0.5 cm 92.8% sensibility, 60% specificity, 77.3% diagnostic accuracy; US with cut off point 1 cm 82.1% sensibility, 80% specificity, 81.1% diagnostic accuracy; US with cut off point 1 cm, also considering round shape or multiplicity of the adenopathy: 82.1 sensibility, 80% specificity, 81.1% diagnostic accuracy; CT with cut off point 0.5 cm: 92.8% sensibility, 32% specificity, 64.1% diagnostic accuracy; CT with cut off point 1 cm: 85.7% sensibility, 64% specificity, 75.4% diagnostic accuracy; CT with cut off point 1 cm, also considering central necrosis, extracapsular spread, multiplicity of the adenopathy 89.2 sensibility, 60% specificity, 75.5% diagnostic accuracy. CONCLUSIONS: By relating the results obtained from preoperative methods to the anatomopathological analysis of the surgical specimens we can draw the following conclusions: a) a neck positive to palpation in a subject with carcinoma of the upper aero digestive tract must be submitted to neck dissection. Such patients have an 81.1% likelihood of having a metastasis. In these patients the use of radiologic studies of the neck must be restricted to cases with uncertain involvement of retropharingeal, mediastinic, paratracheal lymph nodes or in the follow-up after treatment; b) a neck negative to palpation in a subject with carcinoma of the upper aero digestive tract, must be further investigated. The US and the CT must use a cut-off point of 1 cm to consider a neck positive. Radiologic criteria for malignancy, i.e., multiplicity, roundish shape, central necrosis and capsular invasion do not significantly increase the diagnostic accuracy of the radiographic methods; c) the combined use of US and CT does not offer significant advantages in the detection of metastasis, in any case CT is preferable when primary tumor has to be evaluated; d) the assessment of patients that are negative to palpation and to US and to CT must consider the parameters linked with primary tumor, such as site and size, Broder's grading, Invasive Cell Grading, and thickness.

Distinguishing acyclovir neurotoxicity from encephalomyelitis.

OBJECTIVES: To define the clinical characteristics of acyclovir neurotoxicity and to outline how to distinguish it from viral encephalitis. DESIGN: Case series of acyclovir neurotoxicity. SETTING: All cases reported in Index Medicus or in bibliographic reviews of acyclovir neurotoxicity plus two representative studies of Varicella zoster and Herpes simplex virus encephalitis. SUBJECTS: Thirty-five patients who developed neuropsychiatric symptoms during acyclovir therapy. INTERVENTIONS: Analysis of the patients' demographics, risk factors, acyclovir dosages and duration, clinical and laboratory findings and outcome. MAIN OUTCOME MEASURES: All clinical and laboratory findings that were statistically significantly different from viral encephalitis. RESULTS: The median age was 53.3 years. The most common predisposing factors were the use of other potentially neurotoxic medications (17 cases) and acute or chronic renal failure (15 cases). Acyclovir levels were frequently found above the therapeutic range. The characteristic manifestations were confusion (15 cases), hallucination or delirium (9 cases), agitation (8 cases) and lethargy (10 cases). Few patients had associated tremors (11 cases). Fever, headache, seizures and focal neurologic findings were distinctly rare. Cerebrospinal fluid and computed tomography were normal except in patients with other central nervous system disorders. Symptoms appeared within 2 days of therapy in the majority and resolved completely within several days of discontinuing acyclovir. CONCLUSIONS: Acyclovir neurotoxicity is a self-limiting, dose-dependent phenomenon which is more common in the elderly, in patients with renal failure or in association with other neurotoxic medications. It is distinguished from viral encephalitis by its sudden onset, absence of fever or headache, lack of focal neurologic findings and normal cerebrospinal fluid.

Neuromuscular causes of prolonged ventilator dependency.

We prospectively evaluated 21 patients with prolonged ventilator dependency, to determine the frequency of unsuspected neuromuscular disease as a cause of this condition, and to determine the types of such diseases. Assessment was performed with routine and specialized electrophysiologic procedures. None of the patients had known prior neuromuscular disease, and none had ongoing medical problems that could account for their continued ventilator dependency. Sixty-two percent were found to have a neuromuscular disease severe enough to account for the ventilator dependency. Most of the remaining cases had a contributory neuromuscular disease. In addition to critical illness polyneuropathy, several other significant categories were identified. Myopathic EMG changes were found in 50% of the subgroup assessed by quantitative EMG. We conclude that neuromuscular disease is the most important factor in prolonged ventilator dependency, and that diseases other than critical illness polyneuropathy represent an important cause of this syndrome.

Isolation and partial purification of phthalate ester hydrolyzing enzyme(s) from the brine shrimp, Artemia.

Isolation and 30-fold purification of a di-n-butyl phthalate (DNBP) hydrolyzing enzyme from synchronously hatched larvae of the brine shrimp, Artemia, are reported. The activity of the enzyme increases during larval development simultaneously with the acute toxic action of DNBP on the larvae. The enzyme is not stimulated by 10 mM sodium cholate, is stable for days to weeks in solution at 4 degrees C, indefinitely stable at -70 degrees C and is distinct from the previously reported trypsin- and chymotrypsin-like proteases [1].