Two-year clinical performance of a nanofiller vs a fine-particle hybrid resin composite.

The aim of the study was to evaluate the clinical performance of the nanofiller resin composite Filtek Supreme (3M ESPE) vs the conventional fine hybrid resin composite Tetric Ceram (Ivoclar Vivadent) in stress-bearing posterior cavities. In accordance with a split mouth study design, 50 patients (35.7+/-11.3 years) received at least one pair of Filtek Supreme and Tetric Ceram restorations in each of two comparable class II cavities. To obtain comparability, the adhesive Scotchbond 1 was used for all the restorations. After 2 years, the restorations (total number 112) were scored according to the Ryge criteria. After 2 years (recall rate 100%), the results (%) of the Ryge evaluation for the two groups Filtek Supreme/Tetric Ceram were marginal adaptation: Alfa 96/96, Bravo 2/2, Charlie 2/0, and Delta 0/2; anatomic form: Alfa 98/98, Bravo 0/0, and Charlie 2/2; secondary caries: Alfa 100/100 and Bravo 0/0; marginal discoloration: Alfa 98/100, Bravo 2/0, and Charlie 0/0; surface: Romeo 95/95, Sierra 4/4, Tango 0/0, and Victor 2/2; and color match: Oscar 46/57, Alfa 50/39, Bravo 2/4, and Charlie 2/0. One Tetric Ceram and one Filtek Supreme restoration showed fractures that needed restorative intervention. No severe postoperative sensitivities were reported within the observation period. All restored teeth remained vital; the integrity of all the teeth was scored Alfa. After 2 years, no statistically significant differences (Wilcoxon-Mann-Whitney test) was found between the two restorative materials investigated. Therefore, Filtek Supreme, based on a new nanofiller technology, has proved efficaciousness for clinical use in stress-bearing posterior cavities.

Disappearance of anti-Saccharomyces cerevisiae antibodies in coeliac disease during a gluten-free diet.

BACKGROUND: Anti-Saccharomyces cerevisiae antibodies (ASCAs) are known to be positive in about 65% of Crohn's disease patients, in up to 43% of coeliac disease patients and in 0-5% of healthy controls. Coeliac disease might be an in-vivo model for unravelling the role of mucosal integrity in the formation of ASCAs since mucosal abnormalities normalize during a gluten-free diet (GFD). AIMS: Firstly, to evaluate, retrospectively, the frequency of ASCA positivity in coeliac patients both at diagnosis and during follow-up on a GFD. Secondly, to study the correlation between ASCA positivity and mucosal damage. METHODS: One hundred and eleven patients with histologically proven coeliac disease, positive endomysium antibodies on diagnosis and normalization of trans-glutaminase antibodies (t-TGAs) after successful adherence to a GFD were included. ASCAs, IgA and IgG were tested by enzyme-linked immunosorbent assays both at diagnosis and after the GFD. RESULTS: Eighty-three children and 28 adults were included in this study. The mean age at diagnosis was 4.6 years for children and 48 years for adults. At diagnosis 15/83 (18%) of children were ASCA positive (either IgG or IgA), compared to 17/28 (61%) of adults. After successful adherence to a GFD and normalization of t-TGAs only one child remained ASCA positive (1%) compared to eight adults (29%). Two out of 28 (7%) adults remained positive for both IgA and IgG ASCAs. CONCLUSION: In the majority of patients ASCAs disappeared during a GFD. In children this disappearance of ASCA positivity was more pronounced. This can be explained by the well-known fact that gut permeability normalizes much better in children than in adults. Also, the adults had higher levels of ASCAs at diagnosis. This was probably because they had been exposed to gluten for longer and therefore had more long-lasting damage.

Depth of cure of LED vs QTH light-curing devices at a distance of 7 mm.

PURPOSE: To determine the depth of cure of 5 blue LED curing devices compared to that obtained with 3 QTH curing devices. MATERIALS AND METHODS: The LED curing devices tested were 1) e-Light: 40 s; 2) Elipar FreeLight: 40 s; 3) Elipar FreeLight 2: 20 s and 40 s; 4) Ultra-Lume LED 2: 20 s and 40 s; 5) LEDemetron 1: 20 s and 40 s. The QTH curing devices tested were 1) Optilux 501: standard light guide 20 s and 40 s, turbo light guide 20 s; 2) Elipar TriLight: 40 s; 3) Astralis 10: 20 s. Surface hardness was measured (Zwick Z2.5/TS1S) 10 min after exposure on the top and bottom surface of resin samples (Tetric Ceram A3, 1 to 5 mm; 0.5 mm increment, diameter 5 mm, n = 9) which were cured at a distance of 7 mm from the bottom of the sample to the light-guide tip to simulate a Class II curing situation. A reference sample was cured under direct contact with the light guide. The reference sample with the greatest top surface hardness of all devices measured served as the overall control. A bottom/top surface hardness ratio of > or = 80% of the reference sample cured at zero distance was defined as clinically acceptable for safe curing. A descriptive statistical analysis was carried out. RESULTS: With QTH lamps, the mean maximum resin composite sample thickness which cured sufficiently (relative surface ratio > or = 80%) was: 3 mm for Optilux 501, standard light guide, 40 s; 2.5 mm for Trilight, 40 s; and 1.5 mm for Astralis 10, 20 s. The first-generation LED curing devices FreeLight and GC e-Light, both applied for 40 s, and the Optilux 501 operated for 20 s with the standard and the turbo light guide could not sufficiently cure a 1-mm-thick sample at a distance of 7 mm. The new FreeLight 2 and the Ultra-Lume LED 2 cured resin samples up to 2.5 mm thick in 40 s with a relative surface ratio > or = 80%, while no sufficient depth of cure was found after 20 s exposure time for the FreeLight 2. However, a 1.5-mm depth of cure with the Ultra-Lume LED 2 and the LEDemetron 1 with the 13/11 mm light guide was obtained after 20 s. The LEDemetron 1 equipped with a 13/8 mm light guide reached a depth of cure of 2.0 mm. No significant difference was found between the Elipar FreeLight 2, Ultra-Lume LED 2, and LEDemetron 1 in their overall curing potential (linear statistical model, 5% level, Bonferroni-correction) given 40 s or 20 s of exposure time. CONCLUSION: Application of the first-generation LED curing devices FreeLight and e-Light did not ensure clinically sufficient depths of cure, while the new high-power LED curing devices FreeLight 2, Ultra-Lume LED 2, and LEDemetron 1 showed a curing potential equal to the Optilux 501, given 40 s of exposure time.

Determination of polymerization shrinkage stress by means of a photoelastic investigation.

OBJECTIVE: This study examined the polymerization stress of different established composite resins (Tetric Ceram, Vivadent; EsthetX, Surefil, Dentsply/DeTrey; Clearfil AP-X, Clearfil Photo Posterior, Kuraray; Prodigy Condensable, sds Kerr; Filtek P 60, 3M ESPE; Solitaire 2, Heraeus-Kulzer) by means of a photo-elastic investigation and investigated six new, experimental composite resins, which have been claimed to exhibit less polymerization shrinkage (InTen-S, Vivadent; K 112, K 051, Dentsply/DeTrey; Compox, Pluto, Hermes 3M ESPE). METHODS: Cylindrical cavities (phi 5 mm) in Araldit B epoxide resin plates (40 x 40 x 3 mm3) were pretreated with the Rocatec system to ensure bonding of the composite resin. Ten composite resin specimens of each material, embedded in the Araldit plates, were exposed for 60 s (Elipar TriLight, Standard-mode, 800 mW/cm2). Polymerization contraction stress data (MPa) were calculated at 4 min and 24 h after exposure, based on the diameter of the isochromatic curves of first order obtained from the Araldit-plates. The statistical analysis was carried out with the Wilcoxon test (5% level). RESULTS: After 24 h, the calculated mean polymerization stress values were 4.4+/-0.1 MPa for Tetric Ceram, 4.6+/-0.1 MPa for EsthetX, 3.7+/-0.1 MPa for Z 250, 4.6+/-0.1 MPa for Clearfil AP-X, 4.1+/-0.1 MPa for Prodigy Condensable, 4.0+/-0.1 MPa for Filtek P 60, 4.5+/-0.1 MPa for Surefil, 4,5+/-0.1 MPa for Clearfil Photo Posterior, 5.4+/-0.04 MPa for Solitaire 2, 3.2+/-0.1 MPa for In Ten-S, 3.9+/-0.1 MPa for K 112, 3.1+/-0.04 MPa for K 051, 3.2+/-0.1 MPa for Compox, and 2.0+/-0.1 MPa for Hermes. CONCLUSIONS: The new and experimental composite resins In Ten-S, K 051, Compox, and Hermes showed significantly less polymerization shrinkage stress than the controls (p < 0.0005, Bonferroni correction). For the experimental material Pluto, no determination of isochromatic rings was possible.

Decrease in power output of new light-emitting diode (LED) curing devices with increasing distance to filling surface.

PURPOSE: This study compares the percentage decrease in power output of light-emitting diode (LED) and quartz-tungsten-halogen (QTH) curing devices at different distances between the light guide tip and a radiometer. MATERIALS AND METHODS: Three LED curing devices (Elipar FreeLight/3M ESPE, Luxomax/Akeda, e-Light/GC) were compared to two QTH curing devices (Elipar TriLight/3M ESPE, Optilux 501 conventional and Turbo light guides/Kerr-Demetron). Power density was measured with a Fieldmaster GS/Coherent unit (Sensor LM-3 HTD) at increasing distances from the light guide tip (0 to 20 mm at 1-mm increments, n=6). RESULTS: The mean decrease in power density available for curing at a distance of 10 mm between the light guide tip and the radiometer was 68% for the FreeLight, 83% for the e-Light, 42% for the Luxomax, 38% for the TriLight, 33% for the Optilux with the standard light guide, and 44% for the Optilux with the turbo light guide. The power density of the Luxomax was only 40% of that of the other LED curing devices at 0 mm distance. CONCLUSION: The blue LED curing devices Elipar FreeLight and GC e-Light showed a significantly higher percentage decrease in power output at a distance of 10 mm from the light guide tip to the radiometer compared to the QTH curing devices. Therefore, although blue LED curing devices might have the same curing potential compared to a QTH device when placed in direct contact to a resin composite, blue LED curing devices may not provide a sufficient cure when placed at a clinically relevant distance of 10 mm to the resin composite surface.