Haploidentical BMT and post-transplant Cy for severe aplastic anemia: a multicenter retrospective study.

Patients with refractory severe aplastic anemia (SAA) who lack a matched sibling or unrelated donor need new therapeutic approaches. Hematopoietic SCT (HSCT) using mismatched or haploidentical related donors has been used in the past, but was associated with a significant risk of GVHD and mortality. Recently, the use of post-transplant cyclophosphamide (Cy) has been shown to be an effective strategy to prevent GVHD in recipients of haploidentical HSCT, but the majority of reports have focused on patients with hematology malignancies. We describe the outcome of 16 patients who underwent haploidentical transplantation using a reduced-intensity conditioning regimen with post-transplant Cy. Stem cell sources were BM (N=13) or PBSCs (N=3). The rate of neutrophil engraftment was 94% and of platelet engraftment was 75%. Two patients had secondary graft failure and were successfully salvaged with another transplant. Three patients developed acute GVHD being grades 2-4 in two. Five patients have died and the 1-year OS was 67.1% (95% confidence interval: 36.5-86.4%). In our small series, the use of a reduced-intensity conditioning with post-transplant Cy in haploidentical BMT was associated with high rates of engraftment and low risk of GVHD in patients with relapsed/refractory SAA.

Effect of long-term simulated pulpal pressure on the bond strength and nanoleakage of resin-luting agents with different bonding strategies.

This study evaluated the effects of simulated hydrostatic pulpal pressure (SPP) on the microtensile bond strength (µTBS) to dentin and nanoleakage patterns produced by self-adhesive luting agents after 12 months. Three self-adhesive luting agents (RelyX Unicem [UN], RelyX U100 [UC], and Clearfil SA Luting [SA]) and three conventional luting agents (Rely X ARC [RX], Panavia F [PF], and a two-step self-etching adhesive system [Clearfil SE Bond] associated with Panavia F [PS]) were evaluated. One hundred twenty-three human molars were abraded to expose occlusal surfaces. Resin cements were used to lute cylindrical composite blocks to the teeth either subjected or not to SPP. Sixty specimens were subjected to 15 cm H2O of SPP for 24 hours before and 24 hours or 12 months after cementation procedures. Afterward, restored teeth were serially sectioned into beams with a cross-sectional area of 1 mm(2) at the bonded interface and were tested in tension (cross-head speed of 1 mm/min). Failure mode was determined using scanning electron microscopy (SEM). Data were statistically analyzed by three-way analysis of variance and post hoc Tukey test (p=0.05). Two additional teeth in each group were serially sectioned into 0.9-mm-thick slabs, which were submitted to a nanoleakage protocol with AgNO3 and analyzed with scanning and transmission electron microscopes. The µTBS values of the etch-and-rinse group (RX) were negatively influenced by SPP and long-term water storage with SPP. After 12 months, UC and SA presented premature failures in all specimens when submitted to SPP. SPP increased silver deposition in most groups in both evaluation times. The hydrostatic pulpal pressure effect was material dependent. The storage time without SPP did not affect bond strength. However, long-term SPP influenced the performance of the etch-and-rinse and self-adhesive cements regarding µTBS and nanoleakage pattern, except to UN.

Effect of simulated tooth temperature on the degree of conversion of self-adhesive resin cements exposed to different curing conditions.

OBJECTIVES: This study evaluated the degree of conversion (DC) of two commercial, self-adhesive resin cements (SARCs) using Fourier transform infrared analysis (FTIR) polymerized at simulated prepared tooth surface temperatures and under different curing conditions. MATERIALS AND METHODS: RelyX U100 (U100, 3M ESPE) and Maxcem Elite (MX, Kerr Corporation) were mixed at 25°C and applied to the surface of a horizontal attenuated total reflectance (ATR) unit, which was near room temperature (RT, control) (25°C) or heated to simulate prepared tooth surface temperatures (28°C and 32°C) and then attached to an infrared spectrometer. The products were polymerized using one of three conditions: direct light exposure through a glass slide (DLE), exposure through a 1.5-mm thick ceramic disc overlay (CO) (A2 shade, IPS e.max, Ivoclar Vivadent), or self-curing (SC). FTIR spectra were recorded for 12 minutes (1 spectrum/s, 16 scans/spectrum, resolution 4 cm(-1)) immediately after application to the ATR. The DC was calculated using standard techniques of observing changes in aliphatic-to-aromatic peak ratios before and 12 minutes after curing, as well as during each 1-second interval. DC data (n=7) were analyzed by two-way analysis of variance and Tukey's post-hoc test (p=0.05). RESULTS: Both simulated tooth temperatures significantly increased DC in all groups of MX and in the CO and SC groups of U100 compared with the RT control. For MX, the self-cure groups exposed to tooth temperatures showed DC values similar to those of the CO groups. For U100, the CO groups showed higher DC values than SC groups regardless of temperature. Time-based conversion profiles ranged according to product, temperature, and curing mode. CONCLUSIONS: Causing SARCs to polymerize at simulated tooth temperatures increases DC of SARCs compared with room-temperature curing values, mainly in the SC mode.

Effect of temperature on the degree of conversion and working time of dual-cured resin cements exposed to different curing conditions.

OBJECTIVES: This study evaluated the degree of conversion (DC) and working time (WT) of two commercial, dual-cured resin cements polymerized at varying temperatures and under different curing-light accessible conditions, using Fourier transformed infrared analysis (FTIR). MATERIALS AND METHODS: Calibra (Cal; Dentsply Caulk) and Variolink II (Ivoclar Vivadent) were tested at 25°C or preheated to 37°C or 50°C and applied to a similar-temperature surface of a horizontal attenuated-total-reflectance unit (ATR) attached to an infrared spectrometer. The products were polymerized using one of four conditions: direct light exposure only (600 mW/cm(2)) through a glass slide or through a 1.5- or 3.0-mm-thick ceramic disc (A2 shade, IPS e.max, Ivoclar Vivadent) or allowed to self-cure in the absence of light curing. FTIR spectra were recorded for 20 min (1 spectrum/s, 16 scans/spectrum, resolution 4 cm(-1)) immediately after application to the ATR. DC was calculated using standard techniques of observing changes in aliphatic-to-aromatic peak ratios precuring and 20-min postcuring as well as during each 1-second interval. Time-based monomer conversion analysis was used to determine WT at each temperature. DC and WT data (n=6) were analyzed by two-way analysis of variance and Tukey post hoc test (p=0.05). RESULTS: Higher temperatures increased DC regardless of curing mode and product. For Calibra, only the 3-mm-thick ceramic group showed lower DC than the other groups at 25°C (p=0.01830), while no significant difference was observed among groups at 37°C and 50°C. For Variolink, the 3-mm-thick ceramic group showed lower DC than the 1-mm-thick group only at 25°C, while the self-cure group showed lower DC than the others at all temperatures (p=0.00001). WT decreased with increasing temperature: at 37°C near 70% reduction and at 50°C near 90% for both products, with WT reduction reaching clinically inappropriate times in some cases (p=0.00001). CONCLUSION: Elevated temperature during polymerization of dual-cured cements increased DC. WT was reduced with elevated temperature, but the extent of reduction might not be clinically acceptable.

High-concentrated carbamide peroxide bleaching agents effects on enamel surface.

Concern has been expressed regarding the adverse effects of peroxide-containing tooth bleaching agents on enamel surface. This study examined enamel average surface roughness before (baseline) and after an in-office bleaching protocol and investigated the influence of high concentrations of carbamide peroxide gels on its surface staining and morphology. Flat enamel surfaces were submitted to 35 and 37% carbamide peroxide or to no bleaching treatment (n = 10) and evaluated with a profilometer. Eight specimens from each group were randomly selected and immersed in a 2% methylene blue solution. Afterwards, specimens were ground into powder and prepared for the spectrophotometric analysis. Two remained specimens of each group were examined using a scanning electron microscope. Data were subjected to analysis of variance and Tukey test (P > 0.05). Baseline roughness average was statistically similar for all groups, however, 35% carbamide peroxide produced the roughest enamel surfaces. Different concentrations of carbamide peroxide produced similar staining means and enamel surface morphological alterations.