One-year outcome of selective caries removal versus pulpotomy treatment of deep caries: A pilot randomized controlled trial.

AIM: This study aimed to compare the outcome of SCR and Pulpotomy in teeth with deep caries extending at least 75% into dentine. METHODOLOGY: This two-armed, parallel-group, randomized, superiority trial included vital mature permanent teeth with deep primary or secondary caries diagnosed radiographically as being at least 75% into the thickness of dentine, without clinical signs of symptomatic irreversible pulpitis or radiographic evidence of a periapical lesion. Carious teeth were blindly allocated to receive either SCR or Pulpotomy using computer-generated randomized patient codes concealed in opaque envelopes. All teeth were reviewed clinically and radiographically at 6 months and 1 year post-treatment. Using a significance level of p < .05, the log rank test and Cox proportional hazards regression were used to compare the outcome of SCR and Pulpotomy and to identify potential prognostic factors, respectively. RESULTS: In all, 58 teeth in the SCR group and 55 teeth in the pulpotomy group completed treatment, after excluding 6 teeth because they did not complete the allocated treatment and another due to severe periodontal disease. At one year, 57/58 (98.3%) teeth from the SCR group and 48/55 (87.3%) teeth from the Pulpotomy group were available for analysis. One tooth in the Pulpotomy group (2.1%) and eight teeth in the SCR group (14.0%) required the further intervention of root canal treatment (p < .05). There were no other significant prognostic factors for survival. Overall, 91.4% of teeth treated with either SCR or Pulpotomy survived without requiring further intervention over a period of one year. No other adverse events occurred over the review period. CONCLUSION: Within the limitations of this study, Pulpotomy fares better than SCR in preserving the remaining pulp and periapical health. As a treatment modality, Pulpotomy carries greater cost outlay to patient and takes a longer time to complete treatment than SCR. Long-term follow-up is needed to study the pulpal and restorative outcomes of Pulpotomy and SCR.

The cariogenicity of commercial infant formulas: a systematic review.

AIM: To systematically evaluate the cariogenic potential of various commercially available infant formulas. MATERIALS AND METHODS: A literature search was conducted using Pubmed and Scopus databases for articles published between 1966 and November 2014. Reference lists of all eligible studies were searched. Only human studies were included. Data extraction and risk of bias assessments were performed. RESULTS: Seven of the 83 articles identified were included in this review, of which six studies employed plaque harvesting methods, while one study utilised an intra-oral cariogenicity/in situ model. Three studies compared milk-based formulas (MBFs) and soy-based formulas (SBFs), two compared protein hydrolysate formulas (PHFs) with MBFs and SBFs, four compared formulas with various types of sugar, and two studies compared formulas with varying casein content. Based on a single study, SBFs were significantly more cariogenic than MBFs. Formulas containing only non-milk extrinsic sugars (NMES) and those containing lactose + NMES were found to be significantly more cariogenic than formulas containing only lactose. No significant correlation was found between cariogenicity and casein content in infant formula. The results of studies comparing PHFs with MBFs and SBFs were contradictory. Risk of bias assessment revealed that five studies were at moderate risk of bias, and two were assessed to be at high risk of bias. CONCLUSION: The result for cariogenicity of various types of infant formulas remains inconclusive, thus no concrete recommendations can be made. Further well-designed studies are needed to clarify the effect of casein content on cariogenicity.

X-Ray spectra and electronic correlations of FeSe(1-x)Te(x).

Critical issues concerning emerging Fe-based superconductors include the degree of electron correlation and the origin of the superconductivity. X-Ray absorption spectra (XAS) and resonant inelastic X-ray scattering spectra (RIXS) of FeSe(1-x)Te(x) (x = 0-1) single crystals were obtained to study their electronic properties that relate to electron correlation and superconductivity. The linewidth of Fe L(2,3)-edges XAS of FeSe(1-x)Te(x) is narrower than that of Fe-pnictides, revealing the difference between their hybridization effects and localization character and those of other Fe-pnictides. While no significant differences exist between the Fe L-edge XAS and RIXS of FeSe(1-x)Te(x) and those of Fe-pnictides, Se K-edge and Te K-edge XAS exhibit substantial edge shift, suggesting that the superconductivity in an Fe-Se superconductor is strongly associated with the ligand states. A comparison of the Se K-edge and Te K-edge spectra reveals that the charge transfer may occur between Se and Te. Given the Coulomb interaction and the bandwidth, the spectral results indicate that FeSe(1-x)Te(x) is unlikely to be a weakly correlated system unlike the Fe-pnictides of the "1111" and "122" families. The spectral results further demonstrate that superconductivity in this class of Fe-based compounds is strongly associated with the ligand 4p hole state.

Inhibition of HIV-1 replication by isoxazolidine and isoxazole sulfonamides.

Targeting host factors is a complementary strategy for the development of new antiviral drugs. We screened a library of isoxazolidine and isoxazole sulfonamides and found four compounds that inhibited HIV-1 infection in human CD4+ lymphocytic T cells with no toxicity at IC(90) concentrations. Structure-activity relationship showed that benzyl sulfonamides and a halo-substituted aromatic ring on the heterocycle scaffold were critical for antiretroviral activity. The size and position of the incorporated halogen had a marked effect on the antiretroviral activity. The sulfonamide derivatives had no significant effect on HIV-1 entry, reverse transcription and integration but impaired a step necessary for activation of viral gene expression. This step was Tat-independent, strongly suggesting that the target is a cell factor. A virus partially resistant to the least potent compounds could be selected but could not be propagated in the long term, consistent with the possibility that HIV-1 may be less likely to develop resistance against drugs targeting some host factors. Here, we provide evidence that novel synthetic methods can be applied to develop small molecules with antiretroviral activity that target host factors important for HIV-1 replication.

Inhibition of tRNA-dependent ligase MurM from Streptococcus pneumoniae by phosphonate and sulfonamide inhibitors.

Ligase MurM catalyses the addition of Ala from alanyl-tRNA(Ala), or Ser from seryl-tRNA(Ser), to lipid intermediate II in peptidoglycan biosynthesis in Streptococcus pneumoniae, and is a determinant of high-level penicillin resistance. Phosphorus-based transition state analogues were designed as inhibitors of the MurM-catalysed reaction. Phosphonamide analogues mimicking the attack of a lysine nucleophile upon Ala-tRNA(Ala) showed no inhibition of MurM, but adenosine 3'-phosphonate analogues showed inhibition of MurM, the most active being a 2'-deoxyadenosine analogue (IC(50) 100 microM). Structure/function studies upon this analogue established that modification of the amino group of the aminoalkylphosphonate resulted in loss of potency, and modification of the adenosine 5'-hydroxyl group with either a t-butyl dimethyl silyl or a carbamate functional group resulted in loss of activity. A library of 48 aryl sulfonamides was also screened against MurM using a radiochemical assay, and two compounds showed sub-millimolar inhibition. These compounds are the first small molecule inhibitors of the Fem ligase family of peptidyltransferases found in Gram-positive bacteria.

New synthesis of beta-sultams from pentafluorophenyl sulfonates.

A stereoselective one-pot synthesis of substituted 1,2-thiazetidine 1,1-dioxides (beta-sultams) has been achieved from heterocyclic pentafluorophenyl (PFP) sulfonates. Mild N-O bond cleavage of isoxazolidines followed by intramolecular cyclization of the amine onto the PFP demonstrates the potential utility for using the PFP sulfonate as a valuable precursor to sulfonamides. [reaction: see text].

Inhibition of dimethylarginine dimethylaminohydrolase (DDAH) and arginine deiminase (ADI) by pentafluorophenyl (PFP) sulfonates.

A range of pentafluorophenyl (PFP) sulfonate esters derived from the reaction of PFP vinyl sulfonate and various nitrones are shown to have significant inhibitory activity against the bacterial enzymes DDAH and ADI.

Stressful life events of dental students and salivary immunoglobulin A.

To study the perceived sources of stressful events in dental students and the relationship between their self-perceived stress levels and salivary IgA. Undergraduates as well as postgraduates at the Faculty of Dentistry, National University of Singapore were surveyed one month after the new term. A 38-item dental environmental stress (DES) questionnaire, with subscales of academic work (AW), clinical factors (CF), faculty and administration factors (FA) and personal factors (PF), was used to identify the potential stressors in the dental environment. A 4-point perceived stress scale was used to rank their self-perceived stress levels. Enzyme linked immunosorbent assay method was used to determine the salivary IgA level. One hundred and thirty students (81.3%--valid response rate) participated in the study. Overall, students ranked AW with the highest score (mean 2.76), followed by CF (2.67), FA (2.24) and PF (2.16). Among the 38 items of DES questionnaire, 1st year students perceived "fear of being unable to catch up if behind" as the most stressful event (mean 3.30). For 2nd and 3rd year students, examination and grades had the highest scores (mean 3.28, 3.19, respectively). Completing graduation requirements was the most important stressor for 4th year students (mean 3.89). Post graduates perceived atmosphere created by clinical faculty was most stressful to them (mean 3.05). The mean total perceived stress scores were highest (22.1) in 1st year students and lowest (21.0) in postgraduates, however, no significant different among various classes. First year students had had the lowest IgA secretion rates (geometric mean [GM] 46.8 microg/min), significantly lower (p<0.05) than postgraduates (GM 79.4 microg/min). An inverse correlation was noted between perceived stress scale and log IgA secretion rates (r= -0.20, p= 0.002). AW was also significantly inversely correlated with salivary IgA (r= -0.18, p= 0.04). Dental students in different academic years perceived different important stressors. Salivary IgA secretion rate correlated inversely with self perceived stress.

Identification of novel genes expressed during spermatogenesis in stage-synchronized rat testes by differential display.

The molecular mechanism regulating spermatogenesis at different developmental stages remains largely unknown. In a vitamin A-deficiency (VAD) rat model, five distinct histologically defined, stage-synchronized testes: (i) resting spermatogonia and preleptotene spermatocytes at Day 0 of post-vitamin A treatment (PVA); (ii) early pachytene spermatocytes at Day 7 PVA; (iii) late pachytene at Day 15 PVA; (iv) round spermatids at Day 25 PVA; and (v) elongated spermatids at Day 35 PVA were used to study gene expression profiles by mRNA differential display. Twenty-four differentially expressed cDNA fragments were identified and cloned; oligonucleotide sequence analyses indicated that there are 12 novel gene sequences, half of which share no apparent match in current GenBank/EMBL databases. Other 12 VAD clones share sequence homology to membrane channel and transport, transcription and translation, cell cycle and morphogenesis, inducer and transducer, surface or secreted glycoproteins or enzymes, and other miscellaneous molecules. Semi-quantitative RT-PCR analyses against different stages of VAD testes demonstrated: (i) restricted expression of VAD1.2 and 1.3 (novel) on Day 25 PVA when round spermatids form; (ii) escalating pattern of VAD12 (Cx43) in Sertoli cells; and (iii) relative constant levels of VAD4 (A5D3), VAD26.1 (ribonuclease), and VAD27 (GRP8) in spermatogenesis.

Surface finish of a new hybrid aesthetic restorative material.

This study compared the surface finish of a new hybrid aesthetic restorative material (Reactmer) over time to four different types of existing materials. The latter included a composite (Spectrum TPH), a compomer (Dyract AP) and conventional (Fuji II) and resin-modified glass ionomer cements (Fuji II LC). Six specimens of each material were fabricated and stored in distilled water at 37 degrees C for one week. The materials were subsequently finished with a series of Sof-Lex contouring and polishing disks. The average surface roughness (Ra, microm) of each specimen was measured at three days and three months by a surface profilometer. Storage medium was distilled water at 37 degrees C during the hiatus periods. Data was analyzed by ANOVA/Scheffe's and independent samples t-tests at significance level 0.05. At both time periods, Fuji II and Fuji II LC were significantly rougher than Spectrum, Dyract and Reactmer. For all materials, surface roughness at three days was not significantly different from that at three months. The surface finish of the giomer (Reactmer) was significantly better than conventional/resin-modified glass ionomer cements and comparable to the composite and compomer evaluated. The quality of surface finish for all materials was not significantly affected by long-term storage in water.

Bond strengths of glass ionomer restoratives to primary vs permanent dentin.

An in vitro experiment was conducted to evaluate the shear bond strength of a conventional GIC (glass ionomer cement) and a RMGIC (resin modified glass ionomer cement) when applied to dentin of primary and permanent teeth. Results show that the bond strength of the RMGIC was more than thrice that of the conventional GIC. Fracture analysis showed that the bond failures were cohesive in the cement.

Differential expression of gap-junction gene connexin 31 in seminiferous epithelium of rat testes.

Spermatogenesis, a tightly regulated developmental process of male germ cells in testis, is associated with temporal and spatial expression of certain gap-junction connexins. Our findings by RT-PCR indicate that the Cx31 gene is expressed in testis tissue of adult and postnatal rats. During the postnatal spermatogenic process, the Cx31-specific signal became detectable at 15 dpp and onward by in situ hybridization, and apparently localized in the basal compartment of seminiferous epithelium where active spermatogonia and early primary spermatocytes reside. No signal was found in the luminal region. In adult testes, spermatids of elongation phase were also Cx31 positive. Immunohistochemical analysis with mouse anti-Cx31 antibody gave a similar staining pattern, providing further evidence that the gap-junction protein is abundant in the basal seminiferous epithelium, in accordance with the cellular distribution of Cx31 mRNA. These results represent the first demonstration of Cx31 expression at both transcriptional and protein levels in the seminiferous epithelium of rat testes. Thus, Cx31 may play a role in cell-cell communication during spermatogenesis.

Reinforced glass-ionomer cements: the influence of conditioners on marginal leakage.

The purpose of this in vitro study was to evaluate the influence of conditioners on the enamel and dentine margin sealing ability of three different reinforced glass-ionomer cements. Two Class V preparations were made on the buccal and lingual surfaces of 36 freshly extracted molar teeth. Preparations were solely in enamel or dentine/cementum. The teeth were randomly divided into three groups of 12 and restored with either Ketac Silver (KS), Hi-Dense (HD) or Miracle-Mix (MM) with and without (-C) their respective conditioners. All materials were capsulated and were manipulated according to the manufacturers' instructions. The restorations were finished as recommended by the manufacturers and then stored in saline at 37 degrees C for 1 week, polished, thermally stressed, subjected to dye penetration, sectioned and scored. Rankings in the order of decreasing leakage were as follows: enamel margin KS > KS-C > HD-C > HD > MM > MM-C; dentine margin KS > HD-C > KS-C > HD > MM-C > MM. At the enamel margins, only HD showed a significant increase in leakage when conditioner was not used. At the dentine margin, however, KS had significantly more leakage than KS-C and HD-C had significantly more leakage than HD. There was no significant difference in leakage for MM both with and without conditioner. The influence of conditioners on marginal leakage appears to be both product and tissue specific.

An in vitro microleakage study of the 'bonded-base' restorative technique.

Microleakage associated with a silver-reinforced restorative glass-ionomer cement (Hi-Dense) used with a composite resin (Z100) in a modified Class II bonded-base technique restoration was evaluated. The influence of long-term artificial saliva storage, thermal and load cycling was also determined. Class II composite (Z100) restorations used with a new dental adhesive system (Scotchbond Multi-Purpose Dental Adhesive) were used as controls. Results showed that the bonded-base technique can reduce the leakage observed with the direct composite technique. Thermocycling decreased the leakage at the composite-enamel interface but had no effect on the leakage at the composite-dentine interface or on the leakage patterns of bonded-base restorations. Load cycling had no significant influence on leakage patterns of either type of restorative mode. Storage in artificial saliva resulted in decreased leakage at the composite-enamel interface but had a minor adverse effect at the glass-ionomer-dentine interface.

Hypocalcemia and myocardial function in uremia.

To investigate whether hypocalcemia affects cardiac performance in uremic patients, we studied the hemodynamic changes with short- and long-term correction of hypocalcemia in 4 uremic patients on dialysis using continuous wave Doppler study. At rest, 1 h of intravenous calcium infusion increased calcium level from 1.74 +/- 0.17 to 1.92 +/- 0.16 mmol/l (p less than 0.05). Cardiac output represented by minute distance increased from 10.5 +/- 2.0 to 12.1 +/- 2.5 m (p less than 0.05), but heart rate and blood pressure were unchanged. The peak velocity and acceleration of ascending aortic blood flow increased during calcium infusion. With long-term replacement, calcium level increased from 1.74 +/- 0.17 to 1.94 +/- 0.15 mmol/l (p less than 0.05), but resting hemodynamics were unchanged. On exercise testing, exercise duration increased from 10.6 +/- 1.6 min to 12.9 +/- 1.5 min (p less than 0.01), but hemodynamic parameters at peak exercise were similar. We conclude that acute calcium replacement enhanced cardiac contractility in uremic patients, but cardiac performance at rest and peak exercise was not improved with long-term therapy. This reflects different cardiac responses to acute versus chronic calcium replacement.