Effect of a Diode Laser (445 nm) on Polymerization Efficiency of a Preheated Resin Composite Used for Luting of Indirect Composite Restorations.

PURPOSE: The aim of this study was to evaluate the polymerization efficiency of a preheated resin composite used as a luting agent for indirect restorations light-cured by a blue diode laser (445 nm). METHODS: Bronze molds were used to prepare cylindrical specimens of a laboratory composite (Ceramage) with dimensions 2, 3, and 4 mm in height and 8 mm in diameter. The molds had additional height of 120 µm for the placement of the preheated resin composite. A nanohybrid resin composite (Enamel Plus HRi) was preheated at 55°C to use as a luting agent. Photopolymerization was followed for 20 seconds using three light sources: a diode laser emitting at 445 nm (SiroLaser Blue) and two light-emitting diode (LED) units (Bluephase Style and Valo). Degree of conversion (DC) of the preheated resin composite was evaluated using Fourier transform infrared spectroscopy. RESULTS: The results indicated that the main effects of the analysis were significant for both material thickness (p<0.001) and polymerization method (p<0.001). The preheated resin composite was not polymerized under 4-mm-thick specimens, independent of the light-curing unit. For 2-mm material thickness, there was no difference among the three light-curing units (p=0.383), while 3-mm Bluephase Style presented very low DC. CONCLUSIONS: Diode laser (445 nm) achieved better polymerization efficiency at the same fluence compared to the LED unit at 3-mm depth, implying a better mechanical behavior and potential improved adhesion of the luting material to dentin.

The Effect of Denture Adhesives on Denture Quality and Occlusal Force.

INTRODUCTION: Complete dentures (CDs) have been associated with substantial problems regarding edentulous patient's function. Denture adhesives seem to be useful adjuncts to improving retention and stability. METHODS: A clinical study was undertaken to investigate the effect of a denture adhesive (DA) on function in complete denture wearers along with the quality of their CDs. Thirty complete denture wearers participated in the study. The first phase of the experimental procedure comprised 3 groups of measurements performed at 3 distinct time points: the initial measurement (T1), a 2nd measurement after 15 days of DA daily application (T2), and a 3rd measurement following a 15-day washout period (T3). The second phase consisted of the follow-up measurements. The measurements included: recording of relative occlusal force (ROF), distribution of occlusal contacts (DOC) and center of force (COF) using the T-Scan 9.1 device and functional assessment of dentures using the FAD index. RESULTS: The DA use induced a statistically significant increase in ROF (p-value=0.003) and decrease in COF (p-value⟨0.001) and DOC (p-value=0.001). The overall FAD score significantly improved (p-value⟨0.001). CONCLUSIONS: The use of the DA improved the occlusal force, the distribution of occlusal contacts as well as the qualitative characteristics of CDs.

Do composite resin restorations protect cracked teeth? An in-vitro study.

Aims: To evaluate whether bonded resin composite restorations can effectively immobilise the tooth segments in teeth with a synthesised crack under loading, by exploring the impact of the restoration type (direct versus indirect composite resin) and restoration design (inlay versus onlay) on the fatigue resistance. Methods: Sound human third molars underwent large mesio-occluso-distal preparations and a groove was cut to simulate a crack. Standardised procedures were adopted and measures were taken during teeth selection so that systematic error and methodology bias were minimised. The teeth were randomly assigned to four groups. The specimens were submitted to cyclic loading and loaded until fracture or to a maximum of 185,000 cycles. The failure mode was recorded. Results: No failure was observed in 'direct' groups up to the 1000 N force. Survival analysis revealed statistically significant higher survival rates for 'direct' groups compared to 'indirect' groups (χ2 = 11.352, df = 1, p = 0.001) while there was no significant difference between 'inlay' and 'onlay' groups (χ2 = 0.015, df = 1, p = 0.901) (pooled data). Conclusions: Within the limitations of this in-vitro study, it can be concluded that the direct composite resin restorations sufficiently protected the cracked teeth regardless of the cavity design. As there was no statistically significant difference in survival rates between inlays and onlays it is not possible to favour one design type over the other.

Validation of indices for functional assessment of dentures.

AIMS: To validate an assessment of qualities of complete dentures that may relate to functional success. SUBJECTS: A consecutive sample of 131 complete denture wearers took part in the study. SETTING: a Greek department of prosthetic dentistry. INTERVENTION: All participants and their dentures underwent clinical examination. DESIGN: The Functional Assessment of Dentures (FAD) 10-item criteria' describing clinical factors of denture quality was used. The rationale for selecting these particular criteria was to include a range of clinical factors to produce an overall assessment of complete dentures. The 10-item scale was examined for Internal Consistency and Construct Validity providing a summated rating scale whose total score could be used as an index for the quality of dentures. RESULTS: Both intra- and inter-examiner agreement for all 10 dichotomous scale criteria were all good or very good; the intra-examiner Kappa values were 0.72 to 0.91 and the inter- examiner values were 0.72 to 0.99. Statistical analysis revealed that a 7-item summated rating scale could be constructed which has marginally better internal consistency (reliability) and Construct Validity with fewer questions. CONCLUSIONS: The FAD criteria' can be used to give good repeatability. The adjustments made to the original summation scale, if confirmed by new studies, would further increase the practical utility of a FAD index for general dentists. In due course with data from future studies, discrimination on weighting of items will be appropriate to relate the impact of denture quality on quality of life.

Autoantibody against testosterone in a woman with hypergonadotropic hypogonadism.

We demonstrate that antitestosterone autoantibody is produced in a 24-yr-old woman with hypergonadotropic hypogonadism. The serum testosterone level measured by RIA was extremely elevated (5.80 ng/mL); after elution, serum testosterone had returned to a normal female value (0.21 ng/mL). The clinical features were suggestive of no androgen activity. Primary follicles were present in the patent's ovary. After gonadotropin treatment, conception was achieved, and a normal female infant was delivered. A gel filtration study showed that the testosterone-binding activity was eluted at the position of 15,000-kDa Ig. Scatchard analysis revealed a low affinity antibody; the association constant was 0.034 x 10(3) mol-1, and the maximal binding capacity was 162 mumol/mL. An immunoprecipitation study the chain-specific antibodies showed that the antitestosterone autoantibody belonged to kappa-type IgG. This subject is the first reported case with an endocrine disorder who possessed autoantibodies against testosterone.

Ultrasonography and magnetic resonance imaging findings in a patient with an unruptured interstitial pregnancy.

We report a case of an unruptured interstitial pregnancy, which showed characteristic ultrasonographic and magnetic resonance imaging (MRI) findings. Color and pulsed Doppler sonography may facilitate early diagnosis of interstitial pregnancy. MRI may play some role in the diagnosis of this entity when ultrasound studies are insufficient or equivocal.

Myocardial infarction as a complication of pheochromocytoma in a pregnant woman.

Pheochromocytoma is an unusual cause of hypertension during pregnancy. We present a 40-year-old woman who had a myocardial infarction during pregnancy in whom pheochromocytoma was subsequently diagnosed. This disorder carries a high risk of maternal and perinatal mortality, if undiagnosed prior to delivery. Therefore, the diagnosis of pheochromocytoma should be considered in pregnant patients who exhibit a marked fluctuation in hypertension. Urinary concentrations of catecholamines and their metabolites should be measured in such cases.

Plasma exchange in a patient with postpartum HELLP syndrome.

The case of a patient with HELLP syndrome, who was unresponsive to supportive management but successfully treated with plasma exchange, is presented. The significance of plasma exchange in the treatment of HELLP syndrome is discussed.

Immunosuppressive 30-kDa protein in urine of pregnant women and patients with trophoblastic diseases.

Urine samples obtained from normal pregnant women and patients with trophoblastic diseases contain 30-kDa protein that suppresses phytohemagglutinin-induced T cell proliferation. The immunosuppressive protein was measured by a newly developed radioimmunoassay. The 30-kDa protein was demonstrated in almost all urine samples examined, fluid from hydatid vesicles and chorionic extracts, but not in any serum samples except at low levels in some sera from patients with choriocarcinoma. During pregnancy, the level of urinary 30-kDa protein was higher in the first (1625.5 +/- 1212.0 ng/ml, mean +/- S.D.) and second (1457.4 +/- 1332.4 ng/ml) trimesters than in the third trimester (460.6 +/- 419.0 ng/ml). The urinary 30-kDa protein/hCG ratios in patients with choriocarcinoma (8.3 +/- 10.9) were significantly higher than those in patients with hydatidiform mole (0.67 +/- 1.00, P < 0.01) and in all trimesters than those of normal pregnant women (0.54 +/- 0.44 in first trimester, P < 0.05; 0.63 +/- 0.46 in the second trimester, P < 0.05; 0.24 +/- 0.17 in the third trimester, P < 0.01). There is no significant difference between the ratios in hydatidiform mole and normal pregnancy. These findings and the fast disappearance of the 30-kDa protein from the circulation suggest that the 30-kDa protein plays a part in proliferation of trophoblastic cells in, or their invasion into the host by locally suppressing the immune reaction of the host and that the increase in the urinary 30-kDa protein level, in cases of choriocarcinoma, may be due to the malignant transformation of trophoblastic cells resulting in their rapid invasion.

Difference of the hormonal profile at the periovulatory phase in pregnant and nonpregnant cycles of infertile women with unexplained etiology.

Ten women with unexplained infertility, who conceived by intrauterine insemination (IUI) or timed intercourse under controlled ovarian hyperstimulation, were analyzed to investigate the difference of hormonal environment at the periovulatory phase. Forty-two cycles were divided into three groups: the pregnant cycle group, the high luteinizing hormone (LH) group (LH > or = 60 mIU/ml on day -1: the day of human chorionic gonadotropin administration) of nonpregnant cycles and the low LH group (LH < 60 mIU/ml on day -1) of nonpregnant cycles. Progesterone (P4)/estradiol (E2) ratios of the high LH group on day -1 and day 0 were significantly higher than those of each corresponding day in the pregnant cycle. On the other hand, P4/E2 ratio of the low LH group on day +1 was significantly lower. P4/E2 ratio but absolute level of each hormone showed a high indicative value for the estimation of abnormal hormonal environment. It is concluded that the P4/E2 ratio at the periovulatory phase is a good parameter to estimate the efficacy of the method for ovulation induction.

Detection of anti-zona pellucida activities in human sera by the passive hemagglutination reaction.

A simple method of detecting anti-zona activities in human sera has been developed by passive hemagglutination reaction ( PHAR ) using bovine erythrocytes as indicator cells coated with purified porcine zona substance. By this test, 8 of 88 serum samples (9.1%) from infertile women gave positive reactions, whereas only 1 of 90 control sera (1.1%). A positive immunofluorescence (IF) assay confirmed the results of the PHAR in seven of the eight positive samples. Positive PHAR and IF on porcine zonae were abolished after adsorption with porcine erythrocytes, but IF on human zonae was retained by four of eight serum samples, indicating the presence of anti-zona autoantibodies in these infertile sera that were directed to an antigen(s) proper to human zonae.

[Studies on the heterogeneity of urinary HCG molecules by RRA and RIA (author's transl)].

A sensitive bioassay (Radio receptor assay: RRA) for urinary hCG which is independent of plasma half life and metabolism has been developed by utilizing the specific binding of 125I-hCG to 150 approximately 2000g fraction of homogenates of the rat testis. The receptor and immunological activity (RRA/RIA) ratio of urinary hCG in pregnant and trophoblastic diseased women was examined. In addition, the urine of women with normal pregnancies was studied for quantitative and qualitative differences among hCG molecules, by gel filtration on a Sephadex G-100, and each fraction was measured by RRA and radioimmunoassay (RIA). 1) The sensitivity of RRA was 4 ng/ml with a precision (lambda) of 0.03. The intraassay coefficient of variation and that for inter assay were 2 approximately 10% and 12.1% respectively. There was a complete lack of cross reaction with PRL, hCG alpha, hCG beta, and FSH; this indicated a high specificity of the RRA. 2) Receptor reactive hCG in urine throughout pregnancy showed a major peak in the 10th week and declined, but remained fairly constant until the 31st week of pregnancy. The RRA/RIA ratio in urinary hCG of normal pregnancies was highest in the first trimester and lower in the second and third trimester. The average value throughout gestation was 2.04 +/- 0.18 (SE), which was about 2 times greater than that (1.08 +/0 0.11(SE)) of trophoblastic diseases (p less than 0.01). 3) The RRA/RIA ratio in the patients with trophoblastic tumors was highest in the hydatidiform mole and lowest in the chorioepithelioma. 4) When the urine of normal pregnancies was gel filtrated on a Sephadex G-100, it was found that receptor active molecules of hCG were present in urine of the first and second trimester. These results indicated that the RRA/RIA ratio in urinary hCG was distinct in normal pregnancies from trophoblastic tumors and would contribute sufficiently to an early diagnosis and the treatment of successive trophoblastic disease in follow-ups of patients with hydatidiform mole.