The influence of polymerization method on the mechanical properties of dental resins composites

The aim of the study was to asses the influence of the time, method and type of light curing on the compressive strength of dental composites. Dental composite resin (T-Econom, Ivoclar Vivadent) was cured for 10, 30 or 40 sec. with either a commercial conventional halogen light curing unit (LCU)--Hilux, (Benliodlu Dental Inc), or a light emitting diode (LED), LCU-Bluedent LED Smart. The compressive strengths were determined after 72 h on samples 3 mm in diameter and 7 mm high using FPZ 100/1 device. RESULTS: The samples cured with LED LCU for 40 seconds in pulse mode showed the smallest values of compressive strength (245 MPa), while those cured with LED LCU for 40 seconds in ramp mode reached the highest values (295 MPa). Similar values for compressive strength were found for the samples polymerized with conventional halogen LCU and the samples cured with LED LCU in constant mode (283 MPa and 285 MPa, respectively). CONCLUSIONS: Compressive strength depends on the light type and method. Tested LED curing light seems to induce similar compressive strengths as the halogen-based light. Using this conventional light curing unit requires at least 40 seconds of exposure in order to achieve adequate compressive strength. The LED light curing unit should be used in the ramp mode for at least 40 sec, followed by 10 sec in fast mode in order to achieve the best results.     

Dental Sealant Composition-Retention Assessment in Young Permanent Molars

Tooth decay in children and adolescents remains a public health problem, despite prophylaxis and preventive measures being largely available. The aim of our study was to evaluate the clinical behavior of four dental sealants, related to first permanent molar topography and patient age (when sealant was applied for the first time). We assessed, by means of visual inspection and palpation with a dental probe, a group of 200 children, enrolled corresponding to school age-grade (mean age of 7 years at baseline) and randomly divided according to the material used as dental sealant (Admira seal©, Embrace Wet Bond©, Fotoseal©, GC Fuji Triaje©) in 4 groups (n = 50). Sealant clinical evaluation was made at 6-, 12-, 18-month intervals for dental material retention assessment. At 6 months, the sealant detached the most from 3.6 molars, and the material used was Fotoseal© (27.6%). At 12 months, Fotoseal© (48.3%) and GC Fuji Triaje© (41.4%) from 3.6 molars express detachment. At 18 months, 4.6. molars sealed with Admira Seal© (25.7%) and Embrace Wet Bond© (28.6%) lost the sealant. We noticed less detachment in maxillary molars and if sealant was applied around 7 years of age. In conclusion, sealant application on first permanent molars must be encouraged and practitioners can choose between various materials available.     

Diabetes mellitus risk in rheumatoid arthritis: reduced incidence with anti-tumor necrosis factor α therapy

Objective

To examine the association of tumor necrosis factor α (TNFα) inhibitor use and the risk of developing diabetes mellitus in a rheumatoid arthritis (RA) inception cohort.

Methods

Adults diagnosed with RA between January 1, 2001, and December 31, 2009, were identified (n = 1,881). Prevalent cases of diabetes mellitus (n = 294) were excluded. Information on sociodemographic data, medical history, body mass index (BMI), laboratory measures, and medications was collected from the electronic health record. Incident diabetes mellitus was defined using the 2010 American Diabetes Association criteria or physician‐established diagnosis. Time‐varying Cox proportional hazards regression models were used to adjust for age, sex, race, BMI, rheumatoid factor (RF) and anti–cyclic citrullinated peptide antibodies (anti‐CCP), erythrocyte sedimentation rate (ESR), and use of nonsteroidal antiinflammatory drugs (NSAIDs), glucocorticoids, hydroxychloroquine, and methotrexate.

Results

A total of 1,587 incident RA patients without diabetes mellitus were included. The anti‐TNFα users (n = 522) had a lower median age but greater baseline BMI; maximum ESR, RF, and anti‐CCP positivity; and NSAID, glucocorticoid, or methotrexate use. The median followup time for the ever and never TNFα inhibitor users was 44.9 months (interquartile range [IQR] 23.7–73.0 months) and 37.1 months (IQR 16.3–65.1 months), respectively (P < 0.001). Of the 91 patients developing diabetes mellitus, 16 were ever and 75 were never TNFα inhibitor users, yielding incidence rates of 8.6 and 17.2 per 1,000 person‐years (P = 0.048), respectively. Adjusting for covariates, the hazard ratio for incident diabetes mellitus in TNFα inhibitor users was 0.49 (95% confidence interval 0.24–0.99, P = 0.049) compared to the never users.

Conclusion

In this inception RA cohort, anti‐TNFα use was associated with a 51% reduction in risk of developing diabetes mellitus.     

The management of pregnancy in Gaucher disease

Magnetic Resonance Imaging (MRI) has become an established technique in fetal medicine, providing complementary information to ultrasound in studies of the brain. MRI can provide detailed structural information irrespective of the position of the fetal head or maternal habitus. Proton Magnetic Resonance Spectroscopy (¹HMRS) is based on the same physical principles as MRI but data are collected as a spectrum, allowing the biochemical and metabolic status of in vivo tissue to be studied in a non-invasive manner. ¹HMRS has been used to assess metabolic function in the neonatal brain but fetal studies have been limited, primarily due to fetal motion. This review will assess the technique and findings from fetal studies to date.     

3p interstitial deletion: novel case report and review

3p interstitial deletions have emerged in recent years as a new cause of neurodevelopmental delay and intellectual disability. Since the first report of this condition in 1979, 16 cases have been described in the literature, delineating it as a presumptive syndrome. Here, we add a novel case presenting severely delayed neurodevelopment and psychomotor development; facial dysmorphism (square facies, broad forehead, short palpebral fissures, epicanthic folds, broad nasal bridge, and low-set malformed ears); cerebral, cardiac, and genital malformations; hand and feet anomalies; sacral sinus; and hearing impairment. Genetic investigations revealed a del(3)(p12.3p14.1) of 12.5 Mb, including 31 ORFs, among which ROBO2, PDZRN3, MITF, and FOXP1 are known to act in neurodevelopment. The clinical features of our patient are compared with those previously reported in the literature, thus providing further support for the delineation of the 3p interstitial deletion syndrome.